When thinking about (modern) Positive Psychology, people usually associated its onset with Martin Seligman’s term as president of the the American Psychological Association (APA) and his seminal paper in American Psychologist (2000, co-authored with Mihály Csíkszentmihályi).
But the first modern (research-based) sources are almost 50 years older than that. Abraham Maslow was (very likely) the first person to use the term Positive Psychology in a scientific essay. As early as 1954, he wrote about how and why psychology had gone wrong by focusing only on negative behaviors and avoiding the question of what the human experience could be:
If one is preoccupied with the insane, the neurotic, the psychopath, the criminal, the delinquent, the feeble-minded, one’s hopes for the human species become perforce more and more modest, more and more realistic, more and more scaled down. One expects less and less from people. From dreams of peace, affection, and brotherhood, we retreat.
In 1958, Marie Jahoda wrote the book Current Concepts of Positive Mental Health, a book considered to be the first on positive mental health. From the introduction:
Knowledge about deviations, illness, and malfunctioning far exceeds knowledge of healthy functioning. […] Science requires that the previous concentration on the study of inappropriate functioning be corrected by greater emphasis on appropriate functioning, if for no other reason than to test such assumptions as that health and illness are different only in degree.
It´s always good to know on which giant´s shoulders we´re standing on today…