(PhysOrg.com) -- A new study has unexpectedly found that couples married for over 40 years know less about each other than couples who have been together for just a couple of years.
Psychologists from the University of Basel in Switzerland and Indiana University in the US observed the phenomenon in a study of 58 couples in the age group of 19-32 who had been together for an average of 25 months and 20 couples aged 62-78 who had been in their relationship for an average of almost 41 years. The area of least knowledge in partner preferences was food.
The couples, all recruited in Berlin, were asked to rate their own preferences in food, selecting from 40 recipes and food images, movies, selecting from 40 movies available on DVD, and kitchen designs, selecting from 38 designs from online catalogues. They rated their own preferences on a scale of 1-4, from "dont like it at all" to "like it very much", and then rated what they believed would be their partners preferences.
Members of the younger couples accurately predicted their partners' preferences 47% of the time, compared to 40% for the older couples. Slightly lower accuracy for each group was found for movies and kitchen designs.
The researchers suggest, in their paper published in the Journal of Consumer Psychology, the results could mean long-term couples may view their relationship as cemented, that they have little left to learn about each other, or that they tend to pay less attention to each other over time. They may also perceive their partner as largely similar to themselves. On the other hand, people in shorter-term relationships had more motivation to learn more about their partners.
Lending evidence to their hypotheses was the observation that those in long-term relationships were overconfident in their knowledge of their partners preferences in comparison to the younger couples, and they tended to attribute their own preferences for food, design or movies to their partners. Couples who had similar preferences tended to be more accurate in their predictions for their partners than those with different likes and dislikes.
Critics of the research have suggested the older couples may simply belong to a generation in which couples tended to know less about each other than they do today. Another suggested possibility is that in a long-term relationship people may tell white lies to each other to strengthen the relationship, but this could dilute their knowledge of each other.
Regardless of the lower accuracy in predicting their partners preferences, people in long-term relationships reported higher satisfaction with their relationship than those in less well-established relationships.
Explore further: Two definitions for chronic multisymptom illness afflicting Gulf War vets should guide treatment
More information: Older but not wiser--Predicting a partner's preferences gets worse with age, Benjamin Scheibehenne et al., Journal of Consumer Psychology, doi:10.1016/j.jcps.2010.08.001