The 1950s was a decade filled with turmoil, confusion, and hypocrisy. Holden can be seen as a by-product of that, not as the classic "oddball" he is depicted as. This is Salinger's way of critiquing the culture. The time period in which Holden grew up was full of hypocrisy and phoniness, which Holden saw right through. He didn't but into this theory, and thus, it made him different. Thus, the hypocritical society Holden grew up in changed his personality.
One example of this hypocrisy can be seen in the relationship between the sexes. Women were so afraid to be left single in society that they would resort to drastic measures to ensure security. It was most important for women to get married; those who remained single were looked down upon. This led women into marrying almost any man, even if they were not truly in love. Men, in turn, took advantage of this, and often demanded sex from women and in turn offered them security and took their hands in marriage.
Men too were supposed to get married and live this perfect happy lifestyle, but there was more pressure on the women. Holden sees through this theme and doesn't buy into it. He respects the rights of women and loves them for who they are, not just for sexual purposes. This caused Holden's love life to become very limited, as he could not find a girl with the same beliefs as his. He was the rebel without a cause, and was practically alone on his mission. No one can see the world the same as he can, which isolates Holden from people, and he does not develop many friends. It is not his classmates' fault that they won't become friends with him; as they too, are byproducts of the society.