Bryan Lufkin in BBC:
Finding a life partner is considered a major milestone – one that requires deliberation and careful assessment. We want someone whose long-term plans match our own: someone to whom we’re attracted, someone with whom we feel comfortable sharing our home, finances and, maybe, children. This person is our life partner, after all – naturally, we assume we’ll take care with the decision.
But it turns out we may be less selective about whom we spend our lives with than we think. Research shows hidden biases mean we’ll give people a chance, even if they don’t quite meet our criteria. And when we do pick a partner, we’re driven by a psychological tendency called “progression bias” to stay in the relationship, rather than end it.
In other words, we’re hard-wired to be in a romantic relationship, say psychologists, despite trends among young people to shun marriage in favour of a calculated approach to singlehood. Yet, even as the combination of evolutionary instincts and societal pressures steer us towards the coupled life, being aware of our progression bias could help us understand why we pick the partners we do – and why we stay with them.