Question

Driving excessively fast or slow, showing off while driving, or driving aggressively might indicate a driver

Answer 1

is a teenager or has the mental capacity of one.

Answer 2

Aggressive driving behaviour takes many forms. Typical aggressive driving behaviours include speeding, driving too close to the car in front, not respecting traffic regulations, improper lane changing or weaving, etc. The list is long. Most people drive aggressively from time to time and many drivers are not even aware when they are doing it.

Answer 3

@markjhon cite your sources, mate

http://www.unece.org/trans/roadsafe/rs4aggr.html