Why do we compare ourselves to other people?
Because there is frequently no objective standard available, and comparison is how the mind establishes where it stands. It is an automatic evaluative process rather than a character flaw — which matters, because you cannot simply decide to stop.
The underlying theory. Social comparison theory, proposed by Leon Festinger in 1954, holds that people have a drive to evaluate their abilities and opinions, and in the absence of an absolute measure they compare with others — preferentially with those similar to themselves, because those comparisons are informative.
The two directions, which do different things:
Upward comparison, with someone doing better. Can be inspiring and informative when the gap feels closeable, and corrosive when it does not.
Downward comparison, with someone doing worse. Protects self-esteem, which is why people do it after a setback — and can breed complacency or contempt.
Why it has become harder:
Scale. Your ancestors compared themselves with a village. You have access to everyone who is best at everything.
Asymmetric information. You compare your interior with other people's exteriors — your doubts against their announcements. This is the single most important distortion and it is structural, not a failure of perspective.
Selection. Feeds show the best moments of the most successful, algorithmically ranked, which means the comparison set is not a sample of anything.
Metrics. Follower counts, salaries, step counts and grades make comparison numerical and constant where it used to be vague.
What actually helps:
Comparison with your earlier self, which is informative and available.
Curating the input, since muting accounts that reliably produce the feeling is more effective than resolving to feel differently.
Making the comparison explicit. Asking what specifically you envy usually identifies a genuine want worth acting on — envy is information, even when it is unpleasant.
Noticing the denominator, since visible success is selected from an invisible mass of attempts.
Absolute standards where they exist, which is why measurable skills are more satisfying to develop than status.