His antisocial behavior made it difficult for him to maintain friendships.

antisocial 由前缀 anti-（表示"反对、对抗"）和 social（"社会的、社交的"）组成，字面意思是"反对社交的"。这个词描述不愿或无法融入社会交往的行为特征，常指孤僻、不合群或违反社会规范的行为。