DOES marital bliss depend on an active sex life? It sounds like a bears-in-woods and papal-religious-affiliation sort of question, yet around half of studies carried out into the matter suggest the answer is “no”. And this is not just a question of Darbies and Joans, who were at it in their youths, having slowed down as the years have passed. Even reasonably newly married couples, these studies suggest, do not rely on sex to keep their bond strong.

On the other hand, the remaining 50% of investigations have shown the correlation that common sense would predict—namely that in matters matrimonial, sex is crucial. Lindsey Hicks of Florida State University therefore wondered if, as is the case with many things in life, it is all a question of how you ask the question. Many psychological questionnaires permit the respondent time for reflection. Ms Hicks was having none of that. She wanted instant, gut responses.

Ms Hicks’s study, just published in Psychological Science, started off by doing what previous ones have done. She collaborated with a team of colleagues to round up 120 recently married local couples. The partners in these couples were then separated and each asked to fill in a questionnaire that inquired about how satisfied they were with their spouses and how often they had sex (a fact on which, despite what cynics might suspect, husband and wife generally agreed).

Ms Hicks, however, did not leave things there. She suspected the reason why past explorations of this subject have had mixed results is because many people want to believe their marriage is in a good state despite infrequent sex, or that frequent sex should not be important for maintaining a healthy relationship. Wanting to believe something is not, though, the same as actually believing it. So she needed a way to distinguish between the two.

Her answer was what is known as an automatic attitude test. Such tests measure instant feelings. Participants are shown an image and then presented with a word that is either positive (“wonderful”, “outstanding” or “charming”, for example) or negative (“awful”, “disturbing”, “horrible”). When they see this word they must indicate as quickly as they can, using a keyboard that measures their reaction time, whether it is positive or negative. Previous work has shown that faster reaction times to positive words and slower reaction times to negative ones suggest a participant has a positive attitude towards whatever he saw in the image. Slower reaction times to positive words and faster ones to negative words suggest the opposite.

To wield the test for her own purposes, Ms Hicks arranged for participants to work through several sets of words. The first set was a control, in which they ranked the words without seeing an image beforehand. The following sets were preceded either by another control (a picture of the participant him- or herself) or by a picture of the participant’s spouse.

Ms Hicks and her colleagues found that although the frequency with which couples have sex does not have much correlation with how satisfied they claim to be with their partner, it correlates well with their automatic attitudes towards one another. Those who said they had sex with their spouse two or more times a week reacted more quickly to positive words and more slowly to negative ones after seeing an image of said spouse. The opposite was true for those who had sex once a week or less. None of these effects emerged after people saw an image of themselves, or during the initial control.

Ms Hicks’s result does not mean the no-sex brigade are lying when they claim it does not signify. They may genuinely believe what they say. But it does suggest they are fooling themselves. And that is not a matter of mere prurience. If things do start to go wrong in a relationship, and the participants want to patch matters up, then understanding where the real problem lies is important. This is only a single study, of course. But if it is successfully replicated, marriage-guidance counsellors the world over might want to take note.