The paper linked from the article goes into this a bit. (Though I just skimmed it.) The authors started by thinking people who had similar answers would be mo

The paper linked from the article goes into this a bit. (Though I just skimmed it.) The authors started by thinking people who had similar answers would be more attracted, but found that wasn't the case. Just the act of opening up seems to provide the effect. Highlighted in purple on page 367: "Overall, these data suggest that matching in terms of not disagreeing on important attitudes or leading subjects to believe that they and their partners will like each other probably has little impact on the overall closeness subjects achieve through this procedure, or even on their mutual attraction. " http://www.stafforini.com/txt/Aron%20et%20al%20-%20The%20experimental%20generation%20of%20interpersonal%20closeness.pdf http://www.stafforini.com/txt/Aron%20et%20al%20-%20The%20exp...