Harry Benson: A wise woman should think long and hard before proposing to her man this leap day

Harry Benson is director of Bristol Community Family Trust and author of Let’s Stick Together – the relationship book for new parents.

By tradition, 29th February is the one day in every four years when a frustrated lady can pop the question to her hesitant or resistant man! But should she?

It would be easy to write off this old leap day tradition as outdated or even misogynist. But in fact, there’s some really good psychology behind it that can shed light on the current political debate over marriage.

Despite the sea of research showing a strong link between marriage, stability and outcomes, the argument continues over whether the link is down to the act of marriage or merely the kind of people who marry. Personally I think the evidence is clear that both are important. But which side we fall may boil down to our own personal bias, which probably means our own experience of family life.

What is rarely discussed in this debate, however, is how the act of getting married itself could possibly influence the way we behave.

What is never discussed is how the act of cohabiting, whether married or not, could also make an even bigger difference.

A couple of amazing but little known recent US research findings show that commitment is (a) strengthened by our decisions but also constrained by our actions and (b) different for men and women.

Here’s the first finding. Amongst a sample of unmarried couples, neither living together nor having a baby are reliable predictors of stability one year on.

This is such an extraordinary finding that it bears repeating. Take two unmarried couples with similar backgrounds. Say one couple lives together, one couple doesn’t. Alternatively one couple has a baby together, the other couple doesn’t. You can not tell from this information alone which couples will still be together a year later.

What does distinguish the more stable couples are factors such as having a pet together, signing a phone contract together, joining a sports club together, or buying a home together. The common ingredient is that all of these factors require deliberate decisions about the future as a couple. Moving in and having a baby can just kind of happen. Pets and mobile phone contracts can’t!

Most people will recognise that once we’ve made decisions in everyday life, we feel and behave differently. It’s no different for relationships. The act of making a decision about the future changes the way couples behave. This is one of the more plausible explanations for how marriage might have a causal effect, because marriage represents the ultimate decision about the future as a couple.

So here’s the second finding. Amongst a sample of young married couples, men and women tend to be equally committed to each other. Commitment here is measured by dedication – identity as a couple, sense of future together, prioritisation of the relationship, willingness to sacrifice and to forgive. But this is only the case for couples who live together after they got engaged. Amongst those couples who lived together before they got engaged, the men tended to be significantly less committed even five years into married life. In other words, there appears to be a knock-on effect of living together that affects men more than women.

The most plausible explanation for this phenomenon is to do with decisions and inertia. Couples can slide into cohabitation without making any definite decision. But they have to decide to move out if things don’t work out. Making that decision means overcoming inertia. Sliding, deciding and inertia are key to understanding commitment, especially for men.

Although the advent of birth control in the 1970s has fundamentally changed the way we do sex and children, it hasn’t changed the basic psychology of the way we do commitment and stability.

There’s a general lesson for all of us that sliding into cohabitation can trap couples in less-than-ideal relationships that should never otherwise have got off the ground. They then drag on into parenthood and, yes, marriage before finally ending. Ask young 20-somethings how many people they know who have got stuck, prematurely entangled.

How much of today’s epidemic of breakdown amongst unmarried parents is down to this simple explanation? She felt committed because they had moved in together. But he never decided for himself.

So, a wise woman should think long and hard, and then think long and hard again, before proposing to her man this leap day. If he never pops the question himself, how on earth can she be really sure he’s decided for himself?