system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why are car rides soothing for babies?
gpt
Some people will say it's because the car environment reminds babies of the womb. That may be true. It's not a testable hypothesis, though.

The noise and vibration of the car's engine create a monotonous sound and vibration that allow a baby to relax; there is nothing new to see, hear, feel, or do because the car's interior doesn't change. Visual, audible, and sensory stimulation are reduced making it much easier to fall asleep.

There is also speculation that because a parent is in the car the baby may feel safe, too. However that's not a testable hypothesis, either.