Being on someone’s “same wavelength” may be more than just a saying. Psychology researchers at New York University equipped each of 12 high school seniors with a portable, low-cost electroencephalogram (EEG) and gathered brain-wave readings over a semester’s biology classes. The researchers found that when students were most engaged with each other and in group learning, the readings on their EEGs showed brain-wave patterns that rose and dipped synchronously. The synchronous movement was the strongest when students reported that they liked their teacher. Individual students who reported feeling closely tied to their classmates, as well as those who scored highest on the trait of empathy, were most likely to fall into synchrony with classmates in the course of group learning.