Accept your partner for who he or she is and don’t try to change him or her.

There is no shortage of relationship advice available, and one of the most common phrases is: Accept your partner for who he or she is and don’t try to change him or her. While you may be able to make minor tweaks — like getting your significant other to wear dress pants instead of athletic shorts when you go out to eat — trying to make major changes to your partner is not part of a healthy relationship. Here are 4 things you will never be able to change about your significant other — no matter how hard you try.

1. Personality

It is nearly impossible to get someone to behave exactly the way you’d like. People are who they are, and though some personality traits are due to social conditioning, there is no way to turn your partner into a “perfect” version of how you think he or she should act and be. In fact, the propensity for change diminishes greatly once you turn 30, and we’ve known this for over 100 years. Groundbreaking Harvard University psychologist William James’ text, “The Principles of Psychology,” published in 1890, found that your personality stabilizes in adulthood. Part of the text says, per New York Magazine’s Blog Science of Us: “In most of us, by the age of thirty, the character has set like plaster, and will never soften again.” Additional research has shown that our core personality traits have a strong genetic component attached to them and remain constant throughout out lives.

2. How your partner relates to his or her family

Families, especially your partner’s parents, can be a touchy subject, and if any sort of criticism of them comes into the conversation, it’s like walking into a mine field: an explosion can happen at any time. Karl Pillemer, Ph.D., a professor of human development at Cornell University, tells the Huffington Post, “[P]eople’s feelings about their own families are deeply ingrained, and they are not likely to alter significantly after you tie the knot.” He adds that, “[y]ou can come to compromise, but if your spouse and your family don’t get along, pressing for change is not likely to work. Instead, I’d tell you to give your S.O. a free pass to avoid unnecessary get-togethers. Family togetherness is nice, but not at the expense of your relationship with your partner.”