A five-nation study (Journal of Sexual Medicine) of how long it took the men in 500 couples to ejaculate, from the time that they entered the woman, finds it to be (for the male) reassuringly short: an average of 5.4 minutes, with the longest being 44 minutes, the shortest, half a minute. Surprisingly, to me at any rate, younger (18- to 30-year-old) men took longer, averaging 6.5 minutes compared with 4.3 minutes for over-50-year-olds. Of the different nations, the Turkish men were the quickest (3.7 minutes). Circumcised men lasted longer than the uncircumcised. Condom use did not affect duration.

Bath seats for babies create a false sense of security, according to a study of infant bathing deaths (Child: Care, Health and Development). It identified six cases of under-twos drowning in the UK when placed in bath seats, between 1989 and 2003. Admittedly, this compared with 47 infants, over those years, who drowned in the bath in the absence of seats. But having one seems to lead to inadequate supervision because parents imagined the child was safe.

A study of the role of alcohol in violence by men towards their partners suggests it is not as simple as you might expect (Journal of Consulting and Clinical Psychology). Among men with Antisocial Personality Disorder (APD) - impulsive, amoral, aggressive people - whether they committed 'non-severe' violence to partners was not affected by whether they had been boozing. They were liable to lash out at any time, whereas the dangerousness of men without APD was increased by drink.