Carl Hendrick takes a measured look at short-form video as a learning tool, giving a fair shake to its potential advantages (ex. motivating learners about a new topic).

Still, it’s primarily a cautionary signal. This section, whew:

“Heavy short-form video use is associated with measurable decrements in sustained attention, working-memory efficiency and inhibitory control, with effect sizes large enough to persist after controlling for prior cognitive ability and family background.

The neural evidence has filled in. A 2025 Frontiers fNIRS study reports reduced prefrontal activation during cognitively demanding tasks among heavy short-form users. An EEG study by Yan and colleagues (2024) finds reduced midfrontal theta power, a marker of executive function, in heavy users. A 2025 longitudinal paper on screen-media activities and brain function reports altered connectivity in prefrontal cortex, anterior cingulate, amygdala and striatum: the executive and reward circuits both. The standard caveat applies. Most of this evidence is correlational, the causal direction is partly contested (selection effects matter, since adolescents with worse attention may be drawn to short-form video rather than the other way round), and the experimental work has been small-N and acute. But the convergence across designs, populations and modalities is strong enough that prudent policy should not wait for the field to settle the causal question.”