My Sims get into physical fights constantly

I have been experiencing a bug for the past YEAR!! I steer away from gatherings and having friends over, because 98% of the time a fights break out among my sims. It ALWAYS affects relationships and sims have the icon of being battered and bruised from a fight. Relationships have been severed because of it, and it's frustrating because I stay away from socializing physically and just stick to texting, calling or chatting on the web. Please look into this, because my sims cannot socialize being civilized, there is always a brawl around the corner