Final answer:
Proximity is the key factor in consideration of partners for dates, sex, and long-term relationships.
Step-by-step explanation:
The key factor in consideration of partners for dates, sex, and long-term relationships, according to Sprechler and her colleagues, is proximity.
Research has shown that people are more likely to form relationships with individuals they have regular contact with, such as those who live in their immediate vicinity.
This is because regular contact provides the opportunity to get to know the person better.