What term is used for individuals who keep their opinions to themselves and give in to the influence of others?

The term that accurately describes individuals who keep their opinions to themselves and often yield to the influence of others is "passive." Individuals exhibiting passive behavior typically avoid expressing their feelings or rights, often leading them to conform to the wishes or demands of others. They may do this to maintain peace or to avoid conflict, which can harm their ability to assert their own needs and preferences.

In contrast, the other terms refer to different styles of communication. For instance, dominant individuals tend to assert their opinions and desires over others forcefully. Aggressive behavior involves expressing feelings in a way that may be intimidating or disrespectful to others. Meanwhile, assertive individuals communicate their thoughts and feelings openly and confidently while respecting both their own rights and the rights of others. Thus, "passive" is the term that best fits the description of those who withhold their opinions and often allow others to influence them.