A team from the school of psychology and neuroscience at the University of St Andrews discovered that men are less willing to take part in physical challenges such as skydiving than they used to.
The findings of the research led by Dr Kate Cross have been published in the journal Scientific Reports and was co-authored by Dr De-Laine Cyrenne and Dr Gillian Brown.
Researchers focused on the sensation-seeking personality trait which has been described by the university as the desire to pursue novel or intense experiences even if this involves risk.
A sensation seeking scale, version V (SSS-V) questionnaire was used to find out if people were willing to try various activities.
In the late 1970s more men were more likely to try parachuting, scuba diving or mountaineering than women, but over the years their desire for thrills has decreased.
The male average is now closer to the female average, backing up the argument that some sex differences in behaviour have decreased which is linked to cultural changes.
It is thought the reason for this decrease could be because people are less fit.
Dr Cross said: "The decline in the sex difference in thrill and adventure-seeking scores could reflect declines in average fitness levels, which might have reduced people's interest in physically-challenging activities.
"Alternatively, the questions were designed in the 1970s, so could now be out of date."
The activities suggested in the 1970s may be viewed as less intense now, such as skiing.
Other sex differences were shown to be stable by the study, for example men dislike dull or repetitive activities more than women.