Social psychologist Jonathan Haidt warns of smartphones’ impact on teen mental health, advocating for delaying smartphone use until high school and restricting social media until age 16. He points to the pre-smartphone era as healthier, suggesting flip phones for communication. Haidt emphasizes the negative effects of social media on girls’ mental health and boys’ detachment from real-world activities. To counter this, he suggests keeping schools smartphone-free and promoting real-world play and independence.