Right of Reply: Sharon Breen

WRITING FROM a purely biological perspective, Robin Baker ("The death of the nuclear family") ignores the evidence for the psychological and social value of shared parenting for both adults and children. In 1927 the American psychologist John Watson wrote: "Family standards have broken down. In 50 years, unless there is some change, the tribal custom of marriage will no longer exist." Yet more than 70 years later, marriage (or marriage-like relationships) remains a central element of our social structure.

True, the percentage of children who continue to live in couple families has fallen somewhat over the last 25 years, yet the fact is that four in five still do. But where is the evidence that many modern women choose to parent alone, as Mr Baker suggests?

Lone parenthood is often a transitional phase in today's family formation. Each year, 10 per cent of these lone parents move into married or cohabiting relationships. Research indicates that emotional support is vital to mental and physical well-being. While some women prefer to parent alone, overall lone mothers perceive themselves to be less happy and more stressed, and to have less access to physical and emotional resources, than women living with a partner.

True, there is great uncertainty about the role of fathers. But many researchers think that quality fathering may provide children with unique benefits. Pre-schoolers whose fathers provide 40 per cent of their care demonstrate increased empathy, fewer sexual-stereotype beliefs, and "a greater richness of caring". Most people (including many lone parents themselves) still believe that it is better for a child to live with two parents where possible.