The study – that was launched to tackle prejudice against same-sex parents – found that the difference is most pronounced in families with two mothers, where parents spend an average 40 per cent more time on child-centred activities.

“Our study suggests that children with two-parents-of-the-same-sex families received more focused time from their parents – 3.5 hours a day, compared with 2.5 hours by children with different-sex parents,” added Dr Prickett.

Tor Docherty, chief executive of New Family Social, an organisation supporting LGBT adoptive and foster families, said: “For all adoptive parents, spending time to develop an attachment with a child is key.