| Evaluation | Effect | Average Age | Observations | Experimental Evaluation | Country | Intervention |
|---|---|---|---|---|---|---|
| Love 2005 | 11 | 0 | 1,659 | Yes | United States | Treatment varies: daycare, home visits and both services |
| Harden 2012 | 8 | 0 | 746 | Yes | United States | Weekly home visits, biweekly parent-child group activities |