Under the MicroscopeProf William RevilleIn my column on political correctness, September 28th, 2006, I said "there is very significant evidence that both children and parents fare best in (conventional) stable married families", but I didn't detail the evidence.
I contrasted the conventional married family with single-parent families and same-sex union families. A letter to The Irish Times on October 4th quoted from a review paper by Ellin C Perrin and others published in Paediatrics (Vol. 109, No. 2, February 2002) - "children who grow up with one or two gay and/or lesbian parents fare as well in emotional, social and sexual functioning as do children whose parents are heterosexual". In this article I outline the evidence underpinning the assertion I made on September 28th.
I accept that loving nurturing relationships can exist in any family model, although I support the notion of the primacy of the traditional model. But, what we are talking about here is which family model offers the best overall supporting environment to maximise the probability that the family will thrive.
The traditional family based on a married father and mother and their children has been under pressure since the 1970s. Arguments were made by feminists and others that the traditional model was out of date and that different models should be introduced to cater for "freedom of choice" and equal respect for all kinds of families. We now have 30 years' experience of these other family models. One-parent families in particular have been intensively compared with the traditional family.
UK figures show that the proportion of households with a mother, father and dependent children fell from 38 per cent of all households in 1961 to 23 per cent in 2001, while the percentage of lone-parent households tripled from 2 per cent in 1961 to 6 per cent in 2001. Most lone-parent households are fatherless.
The increase in lone-parent households was due to increasing divorce rates, increasing incidence of births outside marriage, decreasing numbers of marriages and increasing rates of cohabitation.
The percentage of births outside marriage prior to the 1960s was about 5 per cent - by 2000 this figure had reached 40 per cent. Cohabiting unions now comprise 70 per cent of first UK partnerships. Only about 18 per cent of cohabiting couples who do not marry survive together at least 10 years, compared to 75 per cent of couples who marry.
There is scientific consensus based on extensive research that children and adults in single-parent households tend to fare worse than in two-parent households (see, for example, review by Rebecca O'Neill, Civitas, September 2002). Lone mothers tend to be poorer, suffer more from stress and psychological problems, have more health problems and problems interacting with their children than mothers in two-parent households. Non-resident biological fathers are at risk of losing contact with their children and are more likely to have health problems and to indulge in high-risk behaviour.
Children living without their fathers are more likely to suffer poverty and deprivation, to have emotional and psychological problems, to have trouble in school, to have more health problems and to be at greater risk of suffering physical, emotional or sexual abuse.
On the other hand, despite a review of outcomes in same-sex union families quoted at the beginning of this column, there is no scientific consensus in this area. This is a difficult area to research for several reasons. The incidence of homosexuality in the general population is low. The original data from the Kinsey reports cited the incidence of male homosexuality at 10 per cent. However, many more careful surveys since then have found that male homosexuality has an incidence of about 5 per cent and female homosexuality of about 2.5 per cent.
The incidence of same-sex union families is therefore very small, leading to difficulties in getting sample sizes big enough for scientific studies. Another difficulty is that of how homosexuality is defined. For example is erotic arousal by contemplation of members of one's own sex sufficient to define homosexuality or is the performance of a homosexual act also necessary? Is a bisexual also to be classed as a homosexual? And so on.
There are several scholarly reviews of the literature on same-sex parenting in addition to the review quoted at the start of my article. Steven Nock, a professor of sociology at the University of Virginia, carried out a thorough review (2001) of papers in this area and submitted his report as an affidavit for a major same-sex marriage case in Canada (Halpern v Attorney General of Canada, No. 684/00 - Ontario Supreme Court of Justice - easily accessed on Google). Nock reviewed several hundred studies and concluded that all "contained at least one fatal flaw of design or execution" and not one study adhered to accepted scientific standards of research.
I am not a sociologist but I understand the principles of scientific surveys. I found Nock's analysis persuasive. Sample size and composition was a big problem in many of the studies, robbing statistical analysis of power to discriminate. Many studies relied on mothers' self-reporting on their parenting abilities and not on objective measures of the child's wellbeing. And many of the studies compare single lesbian mothers to single heterosexual mothers - comparing children in one kind of fatherless family to children in another kind of fatherless family.
Studies to-date on how well children fare in same sex union families are unreliable. Many other studies reliably tell us that children fare better in traditional married families than in a variety of alternative family forms. The overall evidence starkly highlights the importance to children of being raised whenever possible in the traditional family unit by their mother and father. William Reville is associate professor of biochemistry and Public Awareness of science officer at UCC - http://understandingscience.ucc.ie