Men with smaller testicles are more likely than their well-endowed brethren to be involved in the care of their toddlers, anthropologists at Emory University report. The higher the testosterone ...

If we look across the whole of the mammal branch of the tree of life we find there are many groups of mammals that have ...

What is the average testicle size, and does size affect your testosterone, fertility, and sex drive? We explain what’s normal, at what age your testicles stop growing, why they shrink when you ...

The relative size of a man’s testicles may influence the chances of him being a good father according to a study suggesting a biological basis for parenting abilities in men.

A species of cricket has broken an unlikely world record: largest testicles in relation to body weight. The Tuberous bushcricket's testicles account for 14 percent of its body weight. To put that ...

Men with smaller testes are more likely to be involved in hands-on care of their toddlers, a new study by anthropologists finds. Smaller testicular volumes also correlate with more nurturing ...

Photograph by Steve Hamblin, Alamy But while hissing cockroaches’ testicles are flexible in size, they aren’t particularly huge when compared to other species.

Changes in population density can affect the size of animals’ testes and therefore impact on reproduction, researchers have found. Across the animal kingdom, there is usually a positive ...

Harmful microplastics aren’t only detectable in lungs, bloodstreams, and placenta — they can be found in human testicles, as well, according to a study published in the journal Toxicological ...

A new study finds that "better" fathers have smaller testicles. Here’s why that really doesn't matter so much.

Hence, the large testicles. Social structure also explains why more monogamous primates are less ornamented and have smaller testes than non-monogamous primates.

Men with smaller testes than others are more likely to be involved in hands-on care of their toddlers, a new study conducted by anthropologists at Emory University finds. The Proceedings of the ...