The early bird catches the worm. This means people who wake up early do many things. This may be true. Scientists found that people who sleep early do better in tests. People who sleep and wake up early (early birds) do better than people who sleep and wake up late (night owls). Their brains are different.
The scientists tested 38 people. They answered questions about sleep and tiredness. They had brain scans and did tests. The early birds were less sleepy. They did the tests quicker than the night owls. The scientists said night owls have to get up early for school and work. They always want to sleep late.