About 10 percent of Asia can claim to be descended from Genghis Khan and they are absolutely correct, genetic studies show; the reason is that part of the benefit to rampaging across Asia, the mid-East and into Europe was a lot of sex.

But it isn't just conquering Mongols, even on a small scale violent conflict offers biological rewards to those those who take part in it, say anthropologists who correlated violent raids and combat to reproductive fitness. 

The shirt Matt Taylor wore while being interviewed about the Rosetta space mission set off a media and online shirtstorm. Youtube/ ESA

By Jamilla Rosdahl, University of the Sunshine Coast

Games appear in galleries, does that make them art? blakespot, CC BY

By Ashok Ranchhod, University of Southampton and Vanissa Wanick Vieira, University of Southampton.

Want something a little different for Christmas this year? Caroline Yeldham, courtesy of the Leeds International Medieval Congress

By Iona McCleery, University of Leeds.

With Christmas almost upon us, there will be plenty of frenzied present shopping and meal planning. Haven’t made that Christmas cake yet? Fear not. If you were preparing the festive meal 600 years ago you’d have far more on your plate.

The Paleolithic diet, eating like our ancient ancestors, is a diet fad that seeks to emulate the diet of early humans during the Stone Age. But what does that mean? Almost anything people want because ancestral diets differed substantially over time and geography, notes a paper in The Quarterly Review of Biology.

The review examines anatomical, paleoenvironmental and chemical evidence, as well as the feeding behavior of living animals. While early hominids were not great hunters, and their dentition was not great for exploiting many specific categories of plant food, they were most likely dietary "jacks-of-all-trades."

Relational aggression, such as malicious rumors, social exclusion and rejection, are considered something that girls do more often. The movie "Mean Girls" epitomized it to hilarious effect. A trio of scholars used surveys to show that boys are being shortchanged in popular accounts of mean-ness.

620 randomly selected sixth graders were followed through their senior year, filling out an annual survey talking about victimization. Using group-based trajectory modeling the female co-authors determined that boys are actually meaner than girls - or at least they brag about it more on surveys. Boys were more often to call themselves relational aggression perpetrators while girls reported being victims more.

This has as much in common with actual paleolithic culture as the paleolithic diet does. Flickr/George , CC BY-NC-SA

By Darren Curnoe

Necessity may be the mother of invention, at least if war is a necessity. And perhaps it is.

In the early days of humanity, survival was a combination of hardiness, keen engineering and intelligence - and nothing spurred on technological progress and vast social changes like the need to work together to kill other people, according to a new paper in Journal of the Royal Society Interface.

There has been concern about a lessening of social engagement, mostly created by older people who see young people behaving differently than they did (and do). Last decade it was noted that young people were
less likely to join clubs, had fewer close friends, and were less likely to perceive others as trustworthy.

So young people don't join the Masonic Lodge in their college years. Does that mean they are less social? 

No, there has been an increase in extraversion and self-esteem, according to a paper in Personality and Social Psychology Bulletin. In a review, the authors examined past studies that utilized the Revised UCLA loneliness scale (R-UCLA) to analyze changes in loneliness over time, and gender differences in loneliness.

King's College Chapel: beauty, art, profundity – but truth? Tom Thai, CC BY-SA

By Simon Blackburn, University of Cambridge