Can you accurately judge the results of your actions? This is a big question in the legal system, when it comes to deciding whether you’re guilty for a particular action — and, if you’re guilty, the size and type of your sentence. So the neuroscientist Abigail Baird lobbed a mind-bomb into the legal community last month when she presented a paper arguing that teenage criminals are considerably less able to judge the unpredicted consequences of their actions. As the New Scientist reports:

In Baird’s experiment, carried out with colleague Jonathan Fugelsang, teenagers and adults were shown scenarios on a computer screen, such as eating a salad or swimming with sharks. The subjects had to judge whether each was safe or dangerous. Both groups took longer to decide a scenario was dangerous, but this difference was greater in teenagers. Adults took 1.6 seconds longer to reach a decision while teenagers took 1.75 seconds more.

Brain scans taken during the test show that the prefrontal cortex was more active in the teens, suggesting they were making a greater effort to judge the results of each situation. The adults had more basal ganglia activity, pointing to a more automatic response, Baird told a meeting on Law and the Brain at the Institute of Advanced Legal studies, part of University College London, UK, this week.

Freaky, eh? Neuroscience is one of the most insanely revolutionary areas right now — challenging some of our most dearly-held Enlightenment ideas about personal agency, autonomy, and responsibility.

Though much of this also makes intuitive sense. It’s long been a truism that younger people are more likely to experiment wildly with different behaviors, while older people are more conservative. That’s what experience is, after all: A corpus of data sufficiently large that you can begin to find linkages and patterns unobservable in smaller data sets. Even if their brains are moving at a slower clock speed, older folks can draw inferences that can be much richer than those of younger people. The problem tends to be when older people cease to gather new data, and/or when the inferences they’re drawing from already-gathered data produce conclusions that prevent them from even recognizing new data that lies before them. Then you turn into an old crank.

(Thanks to SciTech Daily for this one!)