Beauty and the Beast is a timeless tale: A lovely girl encounters a not-so-attractive, even beast-like man. There is no love at first sight in this story; Beauty, in fact, finds the Beast repulsive. Over time, however, as Beauty gets to know the Beast, she uncovers his warm nature and her heart softens. Ultimately, the story delivers on its fairy tale ending and Beauty falls in love with Beast despite his appearance.

Ahh, if only love could be like that in real life...

Actually, it is. At least in some instances. Although attractive people do tend to select other attractive people in many romantic relationships, new research by Lucy Hunt, Paul Eastwick, and Eli Finkel indicates that there are predictable exceptions. Couples who spark a romantic relationship shortly after meeting are most likely to match in physical attractiveness; however, when people get to know each other well over an extended period of time before dating, it’s not unusual to see greater disparity in their physical appeal.

The tendency to pair with someone who is similar in physical, behavioral, and psychological characteristics is known as assortative mating, and this phenomenon has intrigued experts in psychology, sociology, genetics, and even economics for over a century. While assortative mating is a robust finding, scientists disagree about why it occurs. One popular theory argues a market-based explanation: Individuals compete for the most desirable mates, and those who are themselves very desirable are the most successful in this competition. Highly appealing people thus pair with other very appealing people, while moderately appealing people pair with other fairly appealing people, and so forth.

Hunt and colleagues speculated that assortative mating patterns may attenuate as the time a couple spends together before engaging in a romantic relationship increases. Why? Their belief is that romantic desirability is both objective and subjective. The objective component derives exclusively from the physical features of an individual (e.g., eyes, smile, jawline, physique), and it is this component that shows the greatest consensus when an individual is rated by strangers. The objective component is immediately obvious, and drives perceptions of physical attractiveness — at least initially.

The subjective component of romantic desirability, on the other hand, derives from characteristics that are revealed over time and may have a more unique appeal, like sense of humor, creativity, loyalty, and moral character. As individuals get to know each other over time, romantic impressions rely less on the objective and more on the subjective component. Thus, a person who is objectively less appealing (on the basis of physical features) may become subjectively more appealing (on the basis of personal characteristics). In other words, the Beast transforms into Brad Pitt when you get to know him.

To test these ideas, Hunt and colleagues studied 167 heterosexual couples who were involved in long-term relationships. 100 of the couples were married, while 67 of the couples were dating. The average length of the relationship across all couples was over 8 years, though some had dated for only 3 months while others had been together for more than 50 years. All the couples participated in a video-taped interview in which they were asked questions about their relationships, including how long they had known each other before they started dating, and whether or not they had been platonic friends before dating.

Independent coders later viewed the video tapes and rated the physical attractiveness of each partner. These evaluations were made for both members of a couple at the same time (joint assessments) and for each individual in a couple separately (separate assessments), just to be sure that the attractiveness of one member of a couple did not influence the rating of the partner. These two assessments were highly correlated and were consistent across coders.

The data indicated that the longer partners had known each other before they became romantically involved, the less likely they were to be matched in ratings of physical attractiveness. Couples who began dating within a month of meeting each other showed very strong assortative mating. By contrast, partners who had known each other for at least 9 months before dating showed only modest signs of assortative mating.

It may be the case that physical appearance is less important to some people, and that those people choose to wait to cultivate a romantic relationship until they know someone well. On the other hand, it is also possible that physical appearance is important to all people, but that the perception of physical appearance is changed over time by idiosyncratic characteristics (e.g., a devilish charm makes a man more attractive). Regardless of the mechanism, you are less likely to be a matched in objective physical attractiveness if you know your partner well before falling in love.

Does this mean that people who begin dating immediately after meeting are destined for a more shallow, less fulfilling relationship? This question gnawed at me as I reflected on the fact that I met my husband in a bar and started dating him the following week. Thankfully, the answer is no. Hunt and colleagues also assessed relationship satisfaction, and there was no association between assortative mating and relationship satisfaction. Couples who were matched in physical attractiveness were no more or less likely to be satisfied with their relationships than “mismatched” couples.

The study is limited in the sense that it examined only heterosexual couples, and it did not explore whether the length of acquaintance before dating was influenced by the environment in which couples met. Some contexts (e.g., workplaces or classrooms) may be more conducive to cultivating long-term friendships before dating, while other contexts (e.g., nightclubs, cocktail parties) may necessitate a more immediate romantic overture. If you are hoping to couple with a partner who is objectively more attractive than you, consider doing things together in contexts that allow you to get to know your love interest over time. Had Beast met Belle in a bar, chances are there would have been no fairy tale ending.