Age and male erectile responsiveness.

The purpose of the research was to determine (1) the difference in the rate of penile circumference increase per unit time between a group of young and a group of old normal males when exposed to the same erotic movie and (2) the correlation coefficient between penile shaft temperature increase and penile circumference increase. Ten males aged 19-30 years and ten males aged 48-65 years served as subjects. Each subject placed a thermistor and strain gauge on his penis and both outputs were recorded simultaneously on a two-channel recorder. The younger group responded at an erection rate 5.8 times faster than that of the older group. The correlation coefficient, based on the percent approach to oral temperature (98.6 degrees F) and the percent increase in penile circumference, was 0.75.