Spector’s team asked more than 6000 female twins to fill out a confidential questionnaire about how often they achieved orgasm during intercourse and masturbation. They received 4037 complete replies, which included answers from 683 pairs of non-identical twins and 714 pairs of identical twins.
According to a study published this week, up to 45% of the differences between women in their ability to reach orgasm can be explained by their genes.
There are two common ways that researchers compute genetic influence from twin studies however, one known as ‘pairwise concordance’ the other as ‘probandwise concordance’ (some details here).
Probandwise concordance typically suggests much higher levels of influence from the same data.
I’ve not been able to read the full text of the article, so can’t find out what method has been used to calculate concordance, but if anyone has, please get in touch.