I don't see the contradiction in this article

The first few sentences of this article are:

Researchers believe the two opposing views about what would do the most damage to a relationship could explain why marriages break down so often.

Previous research has suggested a similar trend and the prevailing theory was the difference has evolutionary origins.

Men learned over thousands of years to be hyper-vigilant about sex because they can never be absolutely certain they are the father of a child - while women are much more concerned about having a partner who is committed to raising a family.

But the new research suggests it is much more to do with how secure men and women feel in relationships.

While men hide their insecurity by remaining independent and concentrating on sex, women enter more deeply into relationships, putting more store in emotional connection.

The study suggests women are stronger mentally.

Men fret about unfaithful wives because they are obsessed by the sexual side of their relationships — a superficiality linked to their thin personal attachments.

In other words male jealousy is shaped by deep emotional insecurities, say psychologists Dr Kenneth Levy and Dr Kristen Kelly of Pennsylvania State University.

I don't see why the fourth one starts with 'but'. The insecurities felt by men and women are congruent (good word) with what one would expect from evolution.

Men, who cannot be sure of a child's paternity are worried about their partner having sex with another man. Women, who, traditionally, have needed the support and protection of a man to raise children are worried about their partner abandoning them for another woman with whom they have fallen in love.

The reason for the 'but' is given later as

Now Dr Levy and Dr Kelly, whose findings are published in Psychological Science, said they doubted the evolutionary explanation because there is a conspicuous subset of men who are more like women and find emotional betrayal more distressing than sexual infidelity.

So what if there's a subset of men who are more like women. There's no need for all men to behave one way or the other. There's a subset of men who like men...