All of mankind's problems, now, and any time in the past, have been psychological in nature. There are, however, many theologians, particularly of the Christian persuasion, who are accustomed to making the claim that the principle factor responsible for the numerous maladies commonly displayed by man are due to the "original sin".
The "original sin", as the name indicates, merely refers to what is thought to be the first sin committed; both Adam and Eve acquired something without a faculty to use it wisely; they lacked "common sense"; and this remains mankind greatest problem till this day.
History has proven that people do not learn from history; thus, ignorance remains mankind's greatest enemy.