Family Matters No. 100 - May 2018

Who supports equal rights for same-sex couples?

Evidence from Australia
Francisco Perales and Alice Campbell

Abstract

Research from many nations overseas has shown an increasing public acceptance over the past two to three decades of sexual minorities and the rights of same-sex couples. This article investigates how public support has changed in Australia over the last 10 years, with a comparison of 2005 and 2015 data from the Household, Income and Labour Dynamics in Australia (HILDA) Survey. It analyses individuals' perceptions of whether or not gay/lesbian couples should have the same rights as heterosexual couples, and the extent to which factors such as gender, age, education, religiosity, ethno-migrant background, or area of residence are predictive of these attitudes. The findings show a high degree of support for equal rights, up from 40% in 2005 to 66% in 2015. These changes cannot be attributed to compositional changes in population characteristics, and may be the product of cultural or institutional changes at the macro level.

Background

Despite significant progress in the form of policies aimed at promoting social equity by sexual orientation (Roseneil, Crowhurst, Hellesund, Santos, & Stoilova, 2013; Valfort, 2017) in highly developed countries such as Australia, there remain large differences in life outcomes between heterosexual and lesbian, gay and bisexual (LGB) people (Hudson-Sharp & Metcalf, 2016; Plöderl & Tremblay, 2015). For example, recent Australian studies have shown that, compared to "straight"/heterosexual people, both gay/lesbian and bisexual people experience worse mental health, increased psychological distress, lower levels of life and safety satisfaction, and a wage penalty (La Nauze, 2015; Perales, 2016; Powdthavee & Wooden, 2015; Sabia, Wooden, & Nguyen, 2017). This state of affairs constitutes an evident example of inequality of opportunity, and an important violation of the Australian quintessential principle of the "fair go".

The main theoretical paradigm used to explain differences in life outcomes by sexual orientation in the social sciences, the minority stress framework (Meyer, 2003), poses that non-heterosexual people face a number of barriers in their day-to-day lives that affect their ability to function in society. These challenges include distal stressors (cultural heteronormativity, institutionalised stigma) and proximal stressors (experiences of discrimination, felt stigma, internalised homophobia), as well as - for some - stresses associated with the concealment and monitoring of their sexual identities.

This draws attention to the fact that outcome deficits associated with non-heterosexuality are driven by a social environment that is hostile to people whose sexual identities and behaviours do not "conform" to heteronormative societal expectations. That is, suboptimal life outcomes among LGB people have little to do with internal factors but are instead produced and reproduced by the behaviours of others. Indeed, there is robust international evidence in support of these notions. For instance, LGB people who perceive being subjected to discrimination and stigmatisation on the basis of their sexuality exhibit poorer outcomes than those who do not (Doyle & Molix, 2016; Feinstein, Goldfried, & Davila, 2012), non-heterosexual individuals living in more restrictive ideological and institutional environments experience comparatively worse outcomes (Bauermeister, 2014; Hatzenbuehler, 2014; van der Star & Bränström, 2015), and changes in certain laws and/or policies (e.g., the legalisation of same-sex marriage) have positive effects on the wellbeing of LGB people (Everett, Hatzenbuehler, & Hughes, 2016; Hatzenbuehler et al., 2012; Raifman, Moscoe, Austin, & McConnell, 2017).

Long-standing perspectives in sociology and psychology have demonstrated that, for the most part, people's behaviours follow from their beliefs and world views (Kraus, 1995). Consistent with this, individuals' attitudes towards LGB people have been found to significantly predict their intentions (Morrison & Morrison, 2011) as well as their actual behaviours (Mereish & Poteat, 2015) towards people within this collective. Therefore, understanding the factors associated with people's views about LGB issues is important to understanding the mechanisms producing differences in life outcomes by sexual identity, and the social and political change required to reduce these divergences. This poses questions about how attitudes towards LGB people have evolved over time, and about which socio-structural positions are predictive of people holding more (or less) inclusive attitudes.

In this paper, we set out to examine this issue in the Australian context by focusing on individuals' perceptions of whether or not gay/lesbian couples should have the same rights as heterosexual couples, and the extent to which factors such as gender, age, education, religiosity, ethno-migrant background or area of residence are predictive of these attitudes. To accomplish this, we use longitudinal data from the Household, Income and Labour Dynamics in Australia (HILDA) Survey stretching between 2005 and 2015.

Previous empirical evidence

Recent international scholarship reveals that in many parts of the world public acceptance of sexual minorities and support for the rights of same-sex couples have increased over the past two to three decades (Smith, Son, & Kim, 2014b; Valfort, 2017). However, there is still substantial variation between countries. For example, in cross-national data covering the 2001-14 period, the average degree of acceptance of homosexuality in Organisation for Economic Co-operation and Development (OECD) countries on a scale from 1 (least support) to 10 (most support) ranged from 1.6 (Turkey) to 8.3 (Iceland), with the OECD average standing at around 5 (Valfort, 2017). Australia's mean score (6) was slightly above the OECD average, which places Australia as the tenth most supportive country out of 35 OECD countries. Another cross-national survey conducted in 2013 found that 54% of Australians endorsed the statement "same-sex couples should be allowed to marry legally", with Australia ranking eighth of 16 countries surveyed (Smith, Son, & Kim, 2014a). The highest agreement was observed in Sweden (81%) and the lowest in Poland (21%).

Just as there is between-country variability in public attitudes towards sexual minorities and same-sex marriage, so is there within-country variation based on individual characteristics. Recent international studies have identified that factors such as age, gender, religiosity, political ideology, ethnicity, education, income and area of residence are important predictors of people's world views about sexual minorities in general, and the rights of same-sex couples in particular (Armenia & Troia, 2017; Becker, 2012; Haney, 2016; Jäckle & Wenzelburger, 2014; Sherkat, De Vries, & Creek, 2010; Smith, Son, & Kim, 2014b).

The Australian body of associated evidence, however, is limited. Consistent with the international literature, recent studies have identified that people living in Australia hold more positive attitudes towards same-sex marriage if they are female, younger, non-religious, live in a major city and rate their political orientation as being more liberal/progressive (Anderson, Georgantis, & Kapelles, 2017; Sloane & Robillard, 2017; Smith, 2016). However, all but one of these studies were cross-sectional (which precludes examination of trends over time), relied on small and/or non-representative samples (which hinder their ability to make statements about the general Australian population, and to detect effect differences between comparatively small population groups), and contained only limited contextual information on individuals' socio-demographic traits.

Other studies have focused on other attitudes related to homosexuality. For example, using longitudinal data from the Australian Longitudinal Study of Health and Relationships, Patrick and colleagues (2013) investigated the socio-demographic predictors of change in attitudes towards same-sex behaviour (" Sex between two adult men/women is always wrong"). They found that religiosity increased the likelihood of becoming more disapproving and decreased the likelihood of becoming more tolerant. However, their data spanned only two years and was collected over 10 years ago.

In the remainder of this paper, we will provide recent Australian evidence on the trends and predictors of public views about the rights of same-sex couples, and reflect on the implications of our findings for contemporary public policy and debates.

Data

The Household, Income and Labour Dynamics in Australia Survey

Our analyses rely on data from the HILDA Survey (Summerfield et al., 2016). The HILDA Survey is a multipurpose, household panel that, since 2001, has collected annual information from a sample of Australian families. The HILDA Survey is highly representative of the Australian population, and its overall wave-on-wave sample sizes are large - ranging from around 12,000 to 17,000 respondents. In this study, we focus on HILDA Survey data from Waves 5 (2005), 8 (2008), 11 (2011) and 15 (2015), when the study included a question asking respondents about their views on the rights of same-sex couples. Our analytical sample comprises 52,748 observations from 21,743 individuals.

Support for the rights of same-sex couples

The relevant HILDA Survey question asked respondents to rate their degree of agreement with the following statement: "Homosexual couples should have the same rights as heterosexual couples do" on a seven-point Likert scale from "strongly disagree" [1] to "strongly agree" [7]. As with all other questions on social attitudes, this item was placed within a self-complete questionnaire, as opposed to the computer-assisted face-to-face interview. This was done to ensure that respondents' answers did not suffer from social desirability bias due to the presence of an interviewer. On a scale from 1 to 7, the mean of this support variable across all of the HILDA Survey waves containing the requisite information was 4.5 (standard deviation [SD] = 2.3), indicating moderate-to-high levels of support for the rights of same-sex couples.

We also constructed a dichotomous indicator of support for the rights of same-sex couples. This takes the value 0 (no support) when the original, continuous-level variable takes the values 1 to 4, and the value 1 (support) when the original, continuous-level variable takes the values 5 to 7. When using this binary measure, in 53% of the person-year observations respondents reported agreement with the statement that same-sex couples should have the same rights as different-sex couples (Table 1).

Socio-structural predictors

The HILDA Survey collects rich information on individuals' socio-demographic and economic circumstances. This can be used to derive variables capturing theoretically important factors potentially predicting people's views about the rights of same-sex couples. Basic descriptive statistics for all of these variables are presented in Table 1.

Gender has been shown to be a strong predictor of views, with women generally having more egalitarian and liberal attitudes towards social issues (Pratto, Stallworth, & Sidanius, 1997). This could be because women have historically been an oppressed social group and so may, as a result, be more sensitive to the oppression of others (Sirin, Valentino, & Villalobos, 2017), or because women are in general more supportive or empathetic than men are, be it due to innate traits or gender-based socialisation (Eagly, Diekman, Johannesen-Schmidt, & Koenig, 2004). In our analyses, we use a dummy variable to capture whether the respondent is female (53.24% of the person-year observations) or male (46.76%).

Table 1: Means and standard deviations on model variables
  Mean % SD
Outcome variables   
Support for rights of same-sex couples (1-7) 4.50   2.29
Support for rights of same-sex couples (0-1)   52.93  
Explanatory variables   
Gender      
Male   46.76  
Female   53.24  
Sexual orientation (in 2012)      
Straight/heterosexual   75.33  
Gay/lesbian   1.10  
Bisexual   0.99  
Other response, or no information   22.58  
Age group      
15-39 years   41.87  
40-59 years   34.36  
60 or more years   23.77  
Highest educational qualification      
Degree or higher   23.52  
Certificate or diploma   29.74  
Year 12   15.05  
Below Year 12, or indeterminate   31.69  
Religiosity      
Not religious   52.88  
Religious   32.27  
No information   14.85  
Ethno-migrant group      
Australian, not Indigenous   76.87  
Indigenous Australian   2.18  
Migrant, English-speaking background   9.97  
Migrant, non-English-speaking background   10.98  
Income quartile      
Bottom quartile   25.00  
2nd quartile   25.00  
3rd quartile   25.00  
Top quartile   25.00  
Area remoteness      
Major city   62.28  
Inner regional area   25.00  
Outer regional, remote or very remote area   12.72  
State/territory of residence      
New South Wales   29.63  
Victoria   24.51  
Queensland   21.13  
Western Australia   9.42  
South Australia   9.26  
Tasmania   3.26  
Australian Capital Territory   2.06  
Northern Territory   0.73  
Survey year      
2005   21.46  
2008   20.86  
2011   28.74  
2015   28.94  
n (observations)  52,748
n (individuals)  21,743

Notes: Percentages may not total exactly 100.0% due to rounding.
Sources: HILDA Survey 2005, 2008, 2011 & 2015

As posed by interest-based theories, people's attitudes about a certain topic are driven by how much stake they have in the issue at hand (Danigelis, Hardy, & Cutler, 2007). Therefore, it is natural to assume that respondents' sexual orientation will be a strong predictor of support for the rights of same-sex couples, with such support being greater among non-heterosexual than heterosexual individuals. Using data from Wave 12 of the HILDA Survey, we constructed a measure of sexual identity that separates respondents into "straight"/heterosexual (75.33%), gay/lesbian (1.10%), or bisexual (0.99%). A residual category identifies those who failed to provide a sexual identity or who were not present in Wave 12 of the study (22.58%).1

Socialisation theory highlights how the social environment in which people are born and grew up can leave a lasting "imprint" on their social attitudes (Perales, Lersch, & Baxter, 2017). When people are raised in more traditional environments (e.g., earlier in time or in countries that are less developed than Australia), their views about social issues should be more traditional - reflecting the prevailing norms at the time in which they were socialised. Therefore, support for the rights of same-sex couples among older Australians and those from non-English-speaking backgrounds should be comparatively weaker.2 We split respondents into three age categories: 15-39 years (41.87%), 40-59 years (34.36%), and 60 or more years (23.77%); and four ethno-migrant groups: Australian-born, non-Indigenous people (76.87%), Indigenous Australians (2.18%), migrants from English-speaking countries (9.97%), and migrants from non-English speaking countries (10.98%).

Education exposes individuals to ideals of meritocracy and humanism, and has as a result been related to the emergence of more egalitarian and progressive views about social issues, for example gender roles or abortion (Campbell & Horowitz, 2016; Ohlander, Batalova, & Treas, 2005). We therefore expect more highly educated individuals to express stronger support towards the rights of same-sex couples than less educated individuals. In our analyses, we account for education through a set of dummy variables capturing respondents' highest educational qualification: degree or higher (23.52%), certificate or diploma (29.74%), Year 12 education (15.05%), and below Year 12 education (31.69%).

Similarly, the intergroup contact hypothesis poses that individuals are more tolerant and supportive of non-traditional groups and practices (e.g., abortion, working women, single parents) if they experience direct exposure to them (Dovidio, Love, Schellhaas, & Hewstone, 2017; Mereish & Poteat, 2015). Since same-sex couples cluster in urban areas, we would expect comparatively higher support of their rights by people residing in those locations. Using the HILDA Survey data, we distinguish between individuals living in major cities of Australia (62.28%), inner regional areas (25.00%), and outer regional, remote and very remote areas (12.72%), as defined in the Accessibility/Remoteness Index of Australia classification (Australian Bureau of Statistics [ABS], 2001).

Although there is debate about this, most religions tend to be unsupportive of sexual diversity, and religious organisations sometimes actively campaign against the rights of non-heterosexual individuals and same-sex couples (Jäckle & Wenzelburger, 2014). Therefore, we would expect religious individuals to be less supportive of the rights of same-sex couples in Australia. Using the available data, we constructed a measure of religiosity based on responses to the following questionnaire item: "On a scale from 0 to 10, how important is religion in your life?" - where higher scores denote a higher importance of religion in people's lives. Respondents with response scores ranging from 0 to 4 are considered as being non-religious (52.88%), while those with scores ranging from 5 to 10 are considered as being religious (32.27%). Those respondents who did not have information on religiosity fall into a residual category (14.85%).3

Inter-group competition theories argue that population groups compete with each other for finite (and often scarce) societal resources, with stronger competition operating between vulnerable groups subjected to financial stress. One way individuals deal with economic threat, and the accompanying threats to their self-esteem and perceived control, is via displaced intergroup competition (Fritsche & Jugert, 2017). As a result, individuals with lower income may have more negative attitudes towards sexual minorities and be less supportive of the rights of same-sex couples than their wealthier peers. Therefore, we also included income quartiles as predictors in our multivariate models. These are constructed using a measure of household, financial-year, disposable, regular income that has been adjusted for inflation using the Consumer Price Index.

Finally, to establish whether there are regional differences in levels of support for the rights of same-sex couples net of all the factors outlined so far, our models include a set of nine dummy variables for each of the Australian states/territories.

Results

Predictors of the level of support for the rights of same-sex couples 2015

We first analysed the relationships between the variables capturing socio-structural factors and our outcome variables measuring attitudes towards the rights of same-sex couples for the most recent survey wave, Wave 15 (2015).

The first two columns of results in Table 2 present the multivariate regression models of support for the rights of same-sex couples in which the explanatory variables are a set of socio-structural factors of interest. Column 1 shows the results of a logit model of a binary outcome variable capturing support (values 5-7 in the scale). The results of the logit model are expressed as odds ratios (ORs), where ORs greater than one denote positive associations and ORs smaller than one denote negative associations. For comparison purposes, Column 2 shows the results of an ordinary least-squares (OLS) model in which the coefficients give the expected change in the level of support (on a scale from 1 to 7) associated with a one-unit increase in the explanatory variables. Coefficients greater than zero denote positive associations, whereas coefficients smaller than zero denote negative associations.

The results of the binary measure of support for the rights of same-sex couples (Column 1, Table 2) reveal a number of interesting and statistically significant patterns. As expected and all else being equal, support for equal rights is more prevalent among women than men (OR = 2.00; p < 0.001); gay/lesbian (OR = 12.34; p < 0.001) and bisexual (OR = 3.90; p < 0.001) individuals than heterosexual individuals; and people in the 15-39 age bracket, compared to people aged 40-59 years (OR = 0.63; p < 0.001) or 60 years or more (OR = 0.43; p < 0.001). Differences by highest educational qualification, however, were not linear: support was greatest amongst degree-educated people, followed by those with school Year 12 education (OR = 0.82; p < 0.01), those with certificates/diplomas (OR = 0.60; p < 0.001), and finally those with below Year 12 education (OR = 0.49; p < 0.001). The results also yield evidence of a strong religious divide: the odds of support of people who identify as being religious are only 30% of those of people who do not (OR = 0.30; p < 0.001). There were also differences by ethno-migrant status. Compared to Australian-born individuals, migrants from English-speaking countries (OR = 1.14; p < 0.05) were more likely to support equal rights, while migrants from non-English speaking countries were less likely to do so (OR = 0.52; p < 0.001). There was no difference in the level of support of Indigenous and non-Indigenous Australians (OR = 0.92; p > 0.1). Relative to people in the bottom quartile of the income distribution, those in the third (OR = 1.15; p <0.05) and highest (OR = 1.27; p < 0.001) quartiles held more supportive views; and so did people who lived in major cities, compared to those who lived in inner regional (OR = 0.81; p < 0.001) or more remote (OR = 0.61; p < 0.001) areas. There were no statistically significance differences by state/territory of residence.

The direction and statistical significance of the associations between the socio-structural factors and the continuous-level measure of support for the rights of same-sex couples (Column 2, Table 2) were strikingly similar to those for the binary measure discussed before.

Table 2: Regression models of support for the rights of same-sex couples

 

 

Characteristics

Year 2015 All years
Logit OLS Logit OLS
1 2 3 4
Gender (ref. Male)
Female 2.00*** 0.68*** 2.02*** 0.85***
Sexual orientation (ref. Straight)
Gay/lesbian 12.34*** 1.32*** 17.24*** 2.39***
Bisexual 3.90*** 0.83*** 2.20*** 1.00***
Age group (ref. 15-39 years)
40-59 years 0.63*** -0.41*** 0.70*** -0.45***
60 or more years 0.43*** -0.89*** 0.39*** -1.12***
Education (ref. Degree or higher)
Certificate or diploma 0.60*** -0.45*** 0.51*** -0.70***
Year 12 0.82** -0.16** 0.59*** -0.52***
Below Year 12, or indeterminate 0.49*** -0.62*** 0.49*** -0.77***
Religiosity (ref. Not religious)
Religious 0.30*** -1.29*** 0.46*** -0.90***
Ethno-migrant group (ref. Australian, not Indigenous)
Indigenous Australian 0.92 -0.08 1.37** 0.34**
Migrant, English-speaking 1.14* 0.15** 1.37*** 0.29***
Migrant, non-English-speaking 0.52*** -0.57*** 0.70*** -0.39***
Income quartile (ref. Bottom quartile)
2nd quartile 1.06 0.03 0.97 -0.06
3rd quartile 1.15* 0.10* 0.98 -0.01
Top quartile 1.27*** 0.16** 1.02 0.01
Area remoteness (ref. Major city)
Inner regional 0.81*** -0.19*** 0.75*** -0.32***
Outer regional, remote or very remote 0.61*** -0.47*** 0.69*** -0.43***
State/territory (ref. New South Wales)    
Victoria 1.10# 0.12** 1.10* 0.09*
Queensland 0.93 -0.08# 0.89* -0.17***
Western Australia 0.96 -0.04 0.80*** -0.25***
South Australia 1.09 0.06 1.18** 0.19**
Tasmania 1.13 0.11 1.08 0.11
Australian Capital Territory 1.20 0.20# 1.46** 0.38***
Northern Territory 1.09 0.18 1.61* 0.26
Number of years since 2005 1.11*** 0.11*** 1.10* 0.09*
Interactions with year
Year * ….
Female     1.00 -0.01**
Gay/lesbian     0.98 -0.10***
Bisexual     1.05 -0.01
40-59 years     0.99* -0.00
60 or more years     1.00 0.01*
Certificate or diploma     1.02* 0.03***
Year 12     1.04*** 0.04***
Below Year 12, or indeterminate     1.01 0.02***
Religious     0.96*** -0.04***
Indigenous Australian     0.96* -0.04*
Migrant, English-speaking     0.98* -0.01#
Migrant, non-English-speaking     0.97*** -0.02**
2nd income quartile     1.01 0.01#
3rd income quartile     1.02* 0.02*
Top income quartile     1.03** 0.02**
Inner regional     1.01 0.01#
Outer regional, remote or very remote     0.99 -0.01
Victoria     1.00 0.00
Queensland     1.00 0.01
Western Australia     1.02* 0.02*
South Australia     1.00 -0.01
Tasmania     1.00 0.00
Australian Capital Territory     0.99 -0.01
Northern Territory     0.96 -0.01
Constant 4.78*** 5.97*** 1.45*** 4.77***
n (observations) 15,265 15,265 52,748 52,748
n (individuals)     21,743 21,743
Pseudo R2 0.13   0.13  
R2   0.19   0.22

Notes: Statistical significance: # 0.10, * 0.05, ** 0.01, *** 0.001. Results from logit models expressed as odds ratios.
Sources: HILDA Survey 2005, 2008, 2011 & 2015

Change over time in the level of support for the rights of same-sex couples, 2005-15

We now move to analyse change over time. Figures 1 and 2 show how the degree of support for the rights of same-sex couples has evolved over the 2005-15 observation period.

Figure 1 captures change over time for the continuous-level measure of support. The results are striking, and reveal a tide of support for the rights of same-sex couples in Australian society. Most noticeably, the percentage of respondents who chose the highest point of the support scale (strongly agree) increased from 19.2% in 2005 to 46.3% in 2015, whereas the percentage of respondents who chose the lowest point of the scale (strongly disagree) decreased from 26.7% in 2005 to 12.9% in 2015. The percentage of people who chose any of the five intermediate responses either remained stable or decreased slightly.

Figure 1: Support for the rights of same-sex couples over time, Likert scale

Figure 1: Support for the rights of same-sex couples over time, Likert scale

Note: Hilda Survey statement: Homosexual couples should have the same rights as heterosexual couples do.
Sources: HILDA Survey 2005, 2008, 2011 & 2015

Figure 2 captures change over time for the binary measure of support, and reveals a very similar trend. In 2005, just 39.8% of the Australian population agreed with the notion that same-sex couples should have the same rights as different-sex couples but this rose to 46.9% in 2008, to 54% in 2011, and ultimately to 66% in 2015.

Change over time in the predictors of support for the rights of same-sex couples, 2005-2015

Columns 3 and 4 in Table 2 present the results of multivariate regression models of support for the rights of same-sex couples in which all of the explanatory variables capturing socio-structural factors are interacted with a variable capturing survey year. These models pool data from 2005, 2008, 2011 and 2015. The coefficients on these interaction terms reveal whether and how the estimated effects of socio-structural factors on attitudes towards the rights of same-sex couples have changed over time. Results in Column 3 are from logit models of the binary support measure, whereas results in Column 4 are from OLS models of the continuous measure of support.

The results for the binary measure (Column 3, Table 2) reveal that, net of compositional differences in socio-structural factors, the odds of supporting the rights of same-sex couples increased by 11% with each additional year since 2005 (OR = 1.11; p < 0.001). The interaction effects are of most analytical interest here, and reveal some evidence of changes over time in subgroup differences in support for the rights of same-sex couples. While many of these interactions were statistically significant, their magnitude was generally small - that is, the effects were not substantially significant. There were, however, noticeable exceptions, which we represent graphically.

Figure 3 shows trends over time in support for the rights of same-sex couples by religiosity. This evidences that the gap in support between religious and non-religious Australians has grown. Support rates from religious Australians were estimated at 25.7% in 2005, compared to 45.5% for non-religious Australians. By 2015, the analogous estimates were 47% for religious Australians, and 76.6% for non-religious Australians. Differences in support by religiosity widened from about 20 percentage points in 2005 to about 30 percentage points in 2015.

Figure 4 shows predictions for differences in support over time by highest educational qualification. Interestingly, the "support premium" associated with holding university-level educational qualifications reduced considerably between 2005 and 2015, particularly relative to holding a Year 12 education. That is, university education seems to be progressively less predictive of views towards the rights of same-sex couples over time.

In addition, the OLS models for the continuous-level measure yielded strong and statistically significant evidence of change over time in the degree of support by sexual identity. As shown in Figure 5, this was due to a "ceiling effect", whereby mean support by gay/lesbian respondents approximated the top of the 7-point Likert scale. This enabled the group of bisexual respondents and, to a lesser extent, the group of heterosexual respondents to catch up in their comparative degree of support over time.

Figure 2: Support for the rights of same-sex couples over time, binary measure

Figure 2: Support for the rights of same-sex couples over time, binary measure

Notes: Shows percentage agreeing to the HILDA Survey statement "homosexual couples should have the same rights as heterosexual couples do". Agreement: scores 5-7 in 7-point Likert scale.
Sources: HILDA Survey 2005, 2008, 2011 & 2015

Figure 3: Support for the rights of same-sex couples over time (binary measure), by religiosity

Figure 3: Support for the rights of same-sex couples over time (binary measure), by religiosity

Notes: Shows proportion agreeing homosexual couples should have the same rights as heterosexual couples in HILDA Survey (agreement: scores 5-7 in 7-point Likert scale). Estimated marginal effects at the means of the control variables.
Sources: HILDA Survey 2005, 2008, 2011 & 2015

Figure 4: Support for the rights of same-sex couples over time (binary measure), by highest educational qualification

Figure 4: Support for the rights of same-sex couples over time (binary measure), by highest educational qualification

Notes: Shows proportion agreeing homosexual couples should have the same rights as heterosexual couples in HILDA Survey (agreement: scores 5-7 in 7-point Likert scale). Estimated marginal effects at the means of the control variables.
Sources: HILDA Survey 2005, 2008, 2011 & 2015

Figure 5: Support for the rights of same-sex couples over time (continuous-level measure), by sexual identity in 2012

Figure 5: Support for the rights of same-sex couples over time (continuous-level measure), by sexual identity in 2012

Notes: Shows proportion agreeing homosexual couples should have the same rights as heterosexual couples in HILDA Survey (agreement: scores 5-7 in 7-point Likert scale). Estimated marginal effects at the means of the control variables.
Sources: HILDA Survey 2005, 2008, 2011 & 2015

Discussion and conclusion

Abundant international and Australian evidence demonstrates that non-heterosexual people remain subjected to discrimination and stigmatisation stemming from negative social attitudes, and that these processes have important negative repercussions on their life outcomes. In this paper we have used longitudinal population-level data to examine the degree of support for equal rights for same-sex couples in Australian society, paying attention to trends over time in the level of support and the socio-demographic characteristics of individuals who express high/low support.

Our HILDA Survey results unambiguously show a high degree of societal-level backing for the notion that same-sex couples should have equal rights to heterosexual couples. In 2015, 66% of the Australian population held that view. The HILDA Survey data also provides evidence of overwhelming social change in this regard; as just under 40% of the Australian population expressed support for equal rights for same-sex couples 10 years earlier, in 2005. If attitudes towards same-sex couples are in fact predictive of stigmatising and discriminating behaviours towards LGB people, the observed trend towards support for equal rights paints a positive picture of the future outcomes of Australian sexual minorities.

These societal changes cannot be attributed to compositional changes in population characteristics, at least in those aspects that we have included in our models. This suggests that social change in this arena may be the product of cultural and/or institutional changes at the macro level. Cross-national comparative research has identified that higher levels of gender equality and less heteronormative policy contexts are two macro-level mechanisms associated with more positive attitudes towards non-heterosexual people (Henry & Wetherell, 2017; Henshaw, 2014; van den Akker, van der Ploeg, & Scheepers, 2013). Over the past decade, most Australian states have improved the legal rights of sexual minorities; for example, by recognising same-sex civil unions, granting same-sex couples adoption rights, expunging historical convictions, and equalising the consent age for homosexual and heterosexual sexual behaviours. These legislative changes, together with an increasingly active LGBTI+ movement, may have contributed to the change in societal attitudes reported here.

While a vast majority of the 2015 Australian population supported equal rights for same-sex couples, there was still a non-negligible fraction that did not (about 34%). This poses the question of whether or not differences in support rates are patterned by socio-demographic characteristics. Our analyses reveal clear evidence that this is the case. As expected, support rates were lower among individuals who were male, religious, heterosexual, aged 40 years or over, not holding a university degree, in the bottom income quartile, a migrant from a non-English speaking background, and living in a regional or remote location.

When we further assessed trends over time in the degree to which these socio-structural positions were predictive of support for the rights of same-sex couples, we found more evidence of continuity than change. There were, however, some exceptions. University-level educational qualifications were found to be less predictive of support in more recent years. This is consistent with diffusion theories of attitude change: higher-status "innovators" adopt non-traditional attitudes first, and over time these attitudes diffuse to lower-status, more traditional groups, such as the less-educated (Pampel, 2011). On the other hand, the gap in support levels by religiosity widened markedly over the 10-year observation period. This is consistent with findings of Patrick and colleagues (2013), who found that religiosity increased the likelihood of developing disapproving attitudes towards same-sex sexual behaviours.

These results have significant implications for policy and practice. Despite a high degree of public support for equal rights by 2015, same-sex couples in Australia were still denied the right to marry and the associated symbolic and practical benefits. Almost all Australian states and territories had allowed same-sex couples to register their relationships, which were treated as de facto unions under federal law and conferred most of the same rights as marriage. However, there is often a significant burden of proof associated with registering a relationship. As a result, while the rights afforded married couples are granted automatically and cannot easily be challenged, same-sex couples have had to jump through several hoops to obtain the same rights (Roberts & Kelly, 2017). Furthermore, unlike marriages, registered relationships are rarely recognised overseas.

In late 2017, at the time of writing this article, the ABS was undertaking a national postal survey to gauge public support for legalising same-sex marriage on behalf of the Australian Commonwealth Government. If the majority of Australians participating in the postal survey voted "yes", then the government would facilitate the introduction into parliament of a private member's bill to legalise same-sex marriage, and allow their members of parliament a free vote on the bill. The results, announced on 15 November 2017, indicated that 62% of the survey respondents voted "Yes" and 38% voted "No", with same-sex marriage becoming legal in Australia in December 2017. These results are very similar to the 66% and 34% figures reported in this study - highlighting the external validity of the HILDA Survey as an instrument to gather public opinion.

The relatively small discrepancy between the HILDA Survey analyses and the ABS Survey results may be due to different factors. First, the ABS Survey asked people about same-sex marriage, instead of the rights of same-sex couples more generally, and some people may not consider marriage to be a "right". Second, 21% of eligible Australians did not participate in the ABS Survey, and these Australians may be more likely to have characteristics associated with support for same-sex marriage (e.g., being younger). Third, some supporters of LGBT issues may have boycotted the ABS Survey - for example, due to perceiving that it would elicit unnecessary national debate and be harmful to LGBT people, due to a lack of support for the institution of marriage or due to the survey's cost.

Regardless, the results of both the ABS Survey and our HILDA Survey analyses evidence that there has been a clear misalignment between public attitudes and recent legislation. In keeping with the democratic principle that national legislation and public policies should reflect (changes in) the public sentiment, they suggest that the Australian law required amendments to become more inclusive and respectful of individuals in same-sex couples. In fact, if the observed social trends in the degree of support continue over the next few years, the fraction of the population that will actively oppose this notion is likely to become negligible. In addition, legislative change may result in positive flow-on effects on the life outcomes of same-sex couples, by reducing the experiences of minority stress that result from discrimination and eliciting feelings of social inclusion (Everett, Hatzenbuehler, & Hughes, 2016; Hatzenbuehler et al., 2012).

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Francisco Perales is Senior Research Fellow at the Institute for Social Science Research & Life Course Centre and ARC DECRA Fellow at The University of Queensland. Alice Campbell is a PhD student at the Institute for Social Science Research & Life Course Centre, The University of Queensland.

Disclaimers and acknowledgements
This research was partially supported by the Australian Research Council Centre of Excellence for Children and Families over the Life Course (project number CE140100027) and by an Australian Research Council Discovery Early Career Researcher Award to Francisco Perales for a project titled Sexual Orientation and Life Chances in Contemporary Australia. The HILDA Project was initiated and is funded by the Australian Government Department of Social Services (DSS) and is managed by the Melbourne Institute of Applied Economic and Social Research (Melbourne Institute). The findings and views reported in this paper, however, are those of the authors and should not be attributed to either DSS or the Melbourne Institute.

1 Since sexual orientation can be fluid and changing (Diamond, 2016), it is not ideal to use information on sexual identity from a single time point. Unfortunately, this is all that is available in the HILDA Survey.

2 In practice, non-English-speaking countries include places that are arguably less progressive than Australia (e.g., South-East Asian countries), as well as places that are arguably more progressive (e.g., the Nordic countries). Australian migration from these source countries is skewed towards the former (Department of Immigration and Border Protection, 2016). Therefore, we expect a negative net effect of non-English-speaking country background on attitudes towards the rights of same-sex couples.

3 Information on religiosity was collected in 2004, 2007, 2010 and 2014, whereas information on attitudes towards the rights of same-sex couples were collected in 2005, 2008, 2011 and 2015. Therefore, we were required to transpose responses to those years in which we have attitude data (e.g., from 2004 to 2005, from 2007 to 2008, etc.).