The parliamentary committee on the bill reported:
Most submitters who opposed the bill were specifically opposed to same-sex couples raising children, as they did not believe gay parents could have the same outcomes for children as heterosexual married parents. This is not supported by the research specifically comparing the heterosexual and homosexual parents. Because these beliefs about lesbian and gay parents and their children are open to empirical test, their accuracy can be tested. The American Psychological Association, Lesbian and Gay Parenting: Summary of Research Findings, found:
there is no evidence to suggest that lesbians and gay men are unfit to be parents or that psychosocial development among children of gay men or lesbians is compromised in any respect relative to that among offspring of heterosexual parents. Not a single study has found children of gay or lesbian parents to be disadvantaged in any significant respect relative to children of heterosexual parents. Indeed, the evidence to date suggests that home environments provided by gay and lesbian parents are as likely as those provided by heterosexual parents to support and enable children’s psychosocial growth.
This was supported by the paper ‘‘(How) Does the Sexual Orientation of Parents Matter?’’ published in the American Sociological Review. Both these papers identify the most significant difference to be the discrimination their parents face. The research states:
we propose that homophobia and discrimination are the chief reasons why parental sexual orientation matters at all. Because lesbigay parents do not enjoy the same rights, respect, and recognition as heterosexual parents, their children contend with the burdens of vicarious social stigma.
We recognise the concern that submitters have about the environments in which children are being raised. However, we believe that the biggest unchecked social change New Zealanders have seen in the last 30 years has not been about homosexual rights, the erosion of marriage or no-fault divorce. We believe the shift in work/life balance from favouring the family to favouring the workplace, needs to be urgently addressed. Many submitters agreed that this shift has had significant consequences for New Zealand families. We were reminded that this was important for both parents as their relationship with their children can become strained where workplace pressures mean they do not have much time to engage with their children and play a significant role in their development. The quality of these most significant relationships is pivotal to children’s success.
In the dying days of the last parliament, the government, ably assisted by the opposition, whipped through a bill excluding gay marriage. The prime minister's justification (apart from his undisclosed deal with Family First) was the protection of children. Apparently stigmatizing kids by refusing to let their parents marry does them good.