'Socio-emotional selectivity theory' is illustrated under the life-span theory and described as the human ability to track time and motivate themselves as per the time-horizons. This theory describes that humans tend to shrink their circle of people or shrink themselves as they age and become more selective. They involve in activities or people who are emotionally purposeful.
In the given situation, the Beth's situation(fewer friends in comparison to her young age) exemplify the 'socio-emotional selectivity theory' as it reflects she has motivated herself to a narrowed circle according to time and exhibits 'relative preference' to have 'rewarding associations'(each relationship, deeply satisfying, enjoyable) with people.
