Rosy retrospection is a proposed psychological phenomenon of recalling the past more positively than it was actually experienced.
Though it is a cognitive bias which distorts one's view of reality, it is suggested that rosy retrospection serves a useful purpose in increasing self-esteem and sense of well-being.
[citation needed] Declinism, the predisposition to view the past more favourably and the future more negatively, may be related to cognitive biases like rosy retrospection.
[8] A 2003 pair of studies tracked 68 and 117 undergraduates, suggesting rosy retrospection is caused by high self-esteem.
[9] A 1995 study tracked 30 employed adults over 2 working weeks, having them report their mood every 2 hours during their waking day, as well as end-of-day and end-of-week reflection.
It also found a negative correlation with the average rating and the exaggerated recollections; suggesting those who consistently experienced stronger emotion recall more accurately.
For a week, the children filled in short emotional questionnaires at random points during their school day.
It indeed found a rosy effect as subjects recalled (and predicted) their positive emotions being stronger than they actually were.
Potentially those who come across and are appealed to join and remain in studies will be those with relatively more free-time, better education, higher wealth and income, etc.
Especially if a subject fails to fully recall their emotions, social convention may bias them to more positive terms in an attempt to answer.