WHY does Tim Hopkins of the Equality Network state "research evidence shows clearly that children do as well with same-sex parents as they do with mixed-sex parents" when there is no such evidence?

(Letters, June 11).

Since 1995 there have only been 55 studies into same-sex parenting, 29 of which are written by the same five authors using the same data set.

The majority of these studies are not based on random samples, preferring instead to interview the author's friends and their friends. Many of the studies are based on small sample sizes and do not ask objective questions.

A notable exception to these failings was a recent study with more than 16,000 data points which studied a child's progress through school. However, the author excluded more than 8000 data points because the participants did not meet a five-year residency criteria. Rather than controlling for this group, he omitted the vast majority of gay and lesbian households, skewing the results in favour of a small group of children raised by same-sex parents who made normal progress through school. A recent review of this work has since corrected the original study and found that "compared with traditional married households - children raised by same sex couples are 35% less likely to make normal progress through school" (D W Allen, Demography, 2013).

Furthermore, a recent review of same-sex parenting studies found "no studies of planned gay fatherhood" (Biblarz and Stacey, Journal of Marriage and Family, 2010), and yet it too found in favour of same-sex parenting.

It would appear that at best there is no evidence supporting Mr Hopkins's assertion, and at worst such research is biased.

Ian Maxfield,

Curlers Rest, Roberton, Biggar.

I WAS disappointed by Father Tom White's ill-informed comments concerning adoption by gay couples, unmarried couples and single people ("Charity's legal bid against gay adoption", The Herald, June 10). Having worked in adoption and fostering for 35 years, I am aware of both the facts and the history.

In the 1970s, ground-breaking research (Children Who Wait) was published in the UK which revealed many children, who could not return home, languishing in either residential care or temporary foster care. On the back of this research, attempts were made to widen the range of people approved, after a thorough assessment, to adopt or foster long-term. Initially, this was mainly single people but increasingly, from the 1990s, included gay and lesbian couples and unmarried couples (although in Scotland, until 2009, gay and lesbian couples could not legally foster – they could adopt). There is no doubt that originally these couples and individuals were treated as second best or "last resort" adopters/carers – only allowed to foster or adopt older, more damaged or disabled children for whom married couples could not be found. However, over time it was recognised that they provided equally skilled, dedicated and loving homes for children as more conventional families.

For some children, because of their traumatic experiences in their family of origin, a differently constituted family could be advantageous. Consequently, this is not a "terrible social experiment" but an increasingly well proven means of meeting the needs of children in care. It does not treat children as "commodities that people have a right to", rather it recognises every child's right to a happy and loving family.

Given that numbers of children in care in Scotland have increased by more than 60% in the last 10 years, it is essential that people who think they may be able to offer a child or children a good home, but are not a married couple are not put off from applying to foster or adopt. They will be thoroughly assessed, in line with all other applicants, to ensure they have appropriate backgrounds, motivation and attributes. However, their applications will be welcomed by every local authority or adoption society other than St Margaret's.

Kirstie Maclean,

38 Spottiswoode Street, Edinburgh.