Age of ReasonJay Giedd, a pediatric psychiatrist, has stated that the point of intellectual maturity, the so called "age of reason", comes about the age of 25. In women, it is reached a year or two earlier.
According to Giedd, "Teenagers' brains are not broken; they're just still under construction."
Source: "Brain immaturity can be deadly" by Elizabeth Williamson
The Difference in Adult Brains and Adolescent BrainsAdults think with the prefrontal cortex. That's the rational portion of the brain.
Teens think with the amygdala. That's the instinctual and emotional portion of the brain.
Recent studies, such as the one done by NIH's Institute of Mental Health and UCLA's Laboratory of Neuro Imaging, show that many life changing decisions such as marriage and serving in the military are made before adolescent brains are fully ready to make such decisions.
Dr. Lauren Steinberg of Temple University studies teens and decision-making. He states that teen brains are different from adult brains. He said in an interview on CNN that the changes that take place in teen brains make teens want to take more risks and to seek higher and higher levels of stimulation.
"Sometimes stating the obvious helps. In this case, we think it does. Teenagers are not adults. Their bodies are different. So it turns out, are their minds. The fact that teens think differently explains a lot about why they don't act like adults, not in the classroom or at the mall, and certainly not when they get behind the wheel."
"New research from the National Institutes of Health shows teen brains have extra synapses in the areas responsible for assessing risks and making decisions. Many of these synapses are useless and actually get in the way of clear thinking. These extra synapses die off as teens become adults."
"They don't have the same kind of fear that adults do. Teens are different from adults for some really basic physiological decisions. Their brains are simply different. They are wired differently.
Source: CNN Newsnight
And we would add that's why teens shouldn't marry.