What are the traits of President Kennedy that you consider as inherited?

The research on how much of human behavior is hereditary, and how much is acquired through socialization is far from conclusive. So we really cannot say what character traits of Kennedy (which are really perceptions anyway) are inherited. What we can say, however, is what Kennedy's background was, and suggest ways that this background may have shaped his behaviors as President. John F. Kennedy was born into wealth and privilege. His father was Joseph Kennedy, a wealthy businessman who became a close political ally of Franklin Roosevelt. So "Jack" Kennedy, as he was called, was, by virtue of his birth, a wealthy and well-connected young man. He went to Harvard University, and accompanied his father to England, where the older Kennedy served as US Ambassador during the crisis that preceded the outbreak of World War II. Joseph Kennedy was later associated with the appeasement policies of Prime Minister Neville Chamberlain, which he advocated because he thought the nation was woefully unprepared for war. Jack, indeed, wrote an essay while at Harvard called "Why England Slept" on the subject. Military preparedness would be a major theme of Kennedy's campaign for President; he accused former President Eisenhower (and by extension his opponent, Eisenhower's Vice President Richard Nixon) of allowing a "missile gap" to emerge between the United States and the Soviet Union. Kennedy was also sensitive to charges of appeasement after his father was vilified for this stance, and this perhaps contributed to his sometimes hard-line approach to international communism. Kennedy's brand of politics (concern for social issues combined with a militant brand of anti-Communism) was similar to that of his father and indeed many Catholic politicians. While President, he would pursue these policies that can perhaps be traced to his background. It should also be noted that, after the death of his older brother in World War II, John F. Kennedy became the object of many of his father's hopes and ambitions; it was Joseph that pushed his son to enter national politics. So it is difficult to know how much of Kennedy's traits were inherited, but certainly his father played a major role in his ascent to the Presidency and, perhaps, his behavior while in office.
https://millercenter.org/president/kennedy/life-before-the-presidency