Men have more pronounced personalities than women, finds a new study.
Whether it is being loud or quiet, males are more likely to find their defining characteristics early and stick with them.
On the other hand, females are more changeable and likely to adapt their behaviour to circumstances, according to researchers.
But they appreciate consistency in their partner, a review of studies analysing humans and the animal kingdom dating back more than 30 years shows.
"Our study suggests that, while males tend to exhibit more pronounced personalities, including more predictable behaviour, in a range of different contexts, females are more receptive to these traits in males," Dr Wiebke Schuett, from the University of Exeter, who led the study, said.
"We found a surprising level of similarity across a range of species," Schuett added.
The reason for these differences could lie in the theory of sexual selection, the researchers believe.
Originally devised by Charles Darwin it suggests that traits evolve because of the competition between males for female attention.
These attributes can range from peacock feathers to oversized antler horns.
However, while scientists have in the past been confident of the effect of the phenomenon on physical characteristics they have been less sure of its impact personality.
Now they believe that male personalities have developed over time to be more predictable help them get the girl.
Dr Sasha Dall, from the University of Exeter, who led the study, said: "Females like predictability in their males as it allows them to make good long-term decisions, and to deal with changing circumstances if they know their male is consistent.
"It is not one personality trait, such as being aggressive, it is the fact that they always exhibit that trait that matters.
"This body of research suggests that male personality could have evolved in much the same way as signs of physical attractiveness - to help attract a mate."
The findings are published in the journal Biological Reviews.