POSTPUBESCENT TO MATURE FATHERS - INCREASE IN PROGENY QUALITY

In the mouse, offspring born from mature fathers exhibit better behavi oural performances (for spontaneous activity in both sex and learning capacity in males) than those born from post-pubescent fathers. These behavioural variations are not accompanied by other obvious modificati ons. They could correspond to what has been observed in man relating t o the results in a psychometric test undergone by male progeny born fr om very young to mature fathers, These data and those which show a dec rease in mental performance in rats and human males born from mature t o senescent fathers suggest the participation of some genetic factors in these phenomena.