What the research calls this

Sirois F, Pychyl T (2013). Procrastination and the priority of short-term mood regulation: consequences for future self. Social and Personality Psychology Compass, 7(2), 115 to 127 doi

The paper behind the mood repair account. Delaying a task removes the bad feeling that arrived when you thought about it, and removes it at once, so the delay is repaid immediately while the cost lands on a later version of you. The authors frame this as a difficulty managing feeling in the moment rather than as a failure of caring. It is a review that draws a model together, not a trial, so it is best treated as a well supported explanation rather than as an experimental result.

Steel P (2007). The nature of procrastination: a meta-analytic and theoretical review of quintessential self-regulatory failure. Psychological Bulletin, 133(1), 65 to 94 doi

A large pooling of what actually travels with procrastination. The strongest and steadiest links were to how unpleasant the task feels, to impulsiveness, and to low confidence that you can do the thing. Worth knowing, because the popular claim goes further than the evidence: the link to perfectionism was weaker and less consistent than is usually said. Numbers are not reproduced here, because they were not confirmed against the source.