Instinctively people mimic someone they are interested in (So, not always romantically interested in.) This could definitely cause an impact as you would want to portray yourself equally if not more emotionally stable/strong. But then the question comes into play what about when you open up and share your weaknesses? Well, the simple answer is you think that your peers/family/friends have faced something similar or are understanding enough for you to expose yourself.
But, from a purely emotional standpoint. they allow you to express sides of yourself that are typically socially unacceptable. Being ridiculously silly, vulgar or sharing your emotions is almost always frowned upon like you are somehow harming yourself and or others.