Behaviour Driven By the Developing Brain

A young person’s brain matures and develops so it can become an efficient thinking and problem solving machine. It is this development that can affect some of the behaviours and decisions that are made.

There are three key areas of the brain that are still maturing throughout the young adult years. These areas of the brain are responsible for things such as motivation, emotional reactions and processing information.

Some of the ways young people behave during their teenage years can be explained by parts of their brain that are still developing and maturing. Some examples of how the developing brain can influence behaviour can be seen below.

Nucleus accumbens

The nucleas accumbens is a part of the reward system within the brain. It undergoes pronounced developmental changes during adolescents. Adolescents appear to seek rewards more than adults because of differences within reward centres. [1]


The amygdala is responsible for the emotional aspects of memory, such as feelings of like or dislikes to other people and objects. [2]

Prefrontal cortex

The prefrontal cortex is the last part of the brain to mature and it guides complex processing of information including decision making, controlling impulses, anticipating consequences of behaviour and the ability to take in information and understand it, then set goals and plan. [1,3]


The hippocampus is responsible for developing memories. Research has indicated the adolescent hippocampus is vulnerable when alcohol is consumed. [3]


How do these sections of the brain impact behaviour?

The developing brain increases the likelihood that young people will:

  • Seek high risk activities that are exciting but require little effort.
  • Act impulsively, make poor choices and ignore or not think through the negative consequences of their behaviour.
  • Misinterpret facial expressions as anger.
  • Have difficulty maintaining control over their emotions and overreact in certain situations.
  • Behave in a less inhibited way. [4]

These behavioural changes help us understand how the developing adolescent’s brain can affect decisions about alcohol use, contributing to an increased likelihood of harm. Damage to the developing brain can also occur as a result of choices about alcohol use. [1,3]

Being able to understand what is happening to the brain during its development and how this may contribute to the way young people behave, can help parents to consider how to suitably support young people at this time.

[1] Bava, S. & Tapert, S. (2010). Adolescent Brain Development and the Risk for Alcohol and Other Drug Problems. Neuropsychology Review. 20(4):398-41.

[2] Seeley, R., VanPutte, C., Regan, J., & Russo, A. (2011). Seeley’s Anatomy & Physiology, 9th ed. McGrawHill: NY

[3] Monti, P., Miranda, R., Nixon, K., Sher, K., Swartzwelder, H., Tapert, S., White, A. & Crews, F. (2010). Adolescence: Booze, Brains, and Behavior. Alcoholism: Clinical and Experimental Research. 29(2):207–220.

[4] Squeglia, L., Jacobus, J. & Tapert, S. (2009). The Influence of Substance Use on Adolescent Brain Development. Clinical EEG Neuroscience. 40(1):31–38.