“Hey, old hat Come join us, it's just one cigar, it won't kill you. Do you want to hang out with us? Be a cool dude? Do you want to fit in the group?”
This is the first thing that comes to our mind when we think about peer pressure. But what exactly is peer pressure? How does it affect one’s behavior, personality, and character?
When we grow up, we develop relationships which are matured and last longer, and the people in the relationship will mature as well. During teenage, we wouldn’t have developed a ‘personality’, which is continuously evolving and gets set almost towards the late 20s. 
When we ask people what peer pressure exactly is I am sure that the response will be something like I quoted at the beginning. But, peer pressure, actually, is a group of people or a person exerting direct or indirect influence on another individual. It influences not only the way one dress or talks, but also one’s behavior as a whole.  It also defines one’s habits and ideology. But, we are living with a wrong notion about peer pressure that it always has a gloomy impact on an individual, whereas peer pressure has a lot of positive outright effects on an individual too. 
A study has found that a person who is under the influence of good friends or a group is less likely to go into depression or commit suicide. Good friends circle helps an individual to share his or her problems with his or her friends overcome them. Individual differences motivate the individual and also guide them on the right path. We can find positive peer pressure more helpful in teenage. Teenage is one of the most critical times for any individual where one undergoes a lot of changes. This is the time when one is most likely to make wrong decisions as he or she always tries to fit in a group of people. One tries to separate oneself from one’s parents and other family members as one feels that he or she has become an adult and found new freedom to make his or her own choices and decisions. As they spend most of the time in school and in other activities the role of a peer is something that cannot be ignored. In scenarios like this only true friends can help the individual to make the right choices and save them from falling into a deep abyss of the snares and traps laid by bad company and egregious habits. 
Friends can exert pressure on them to leave the habits such as of smoking or intake of drugs. Not only this, but they can also motivate them and try to get better out of the individual like getting better grades or partaking in multiple activities. They assist you to push your limits and encourage you to achieve your goal. They counsel you to bring a constructive change in your personality. They provide you an exposure to help you maintain healthy social relations that will make you understand about human behavior in a wider manner and provide you the experience to deal with problems in a harmonious way. 
As there are two sides to every coin, bad peers do exist. But it is for us to decide what to choose and what not to. We must learn to differentiate between what is good and what is bad for us. Always remember to think for yourself. Trust your institutions, others are not going to walk your journey but you are. All you have to do is to ignore the things that will make your life a lot more complicated. 
During that time, even our peers have the maturity to accommodate us as an individual, and there may not be any pressure as well. And what I observed is that we need not fit in to be part of the group (but this is a later stage of development of social circles and relationships). I say that because I have friends who drink, smoke (but are ethically quite good with others), I do have good relationships with them, I go out with them, we have a nice and meaningful exchange of thoughts, but those haven’t influenced me or none have ever forced me either. Because the thought, action, character trait have almost been set and we define who we are and the people around us very well get adjusted to it. Because relationships, then, are formed on more matured and meaningful aspects of life. There will always be thoughts and interests that are similar despite differences but choosing for yourself and standing by it is the most important.