| Evaluation | Effect | Average Age | Observations | Experimental Evaluation | Country | Intervention |
|---|---|---|---|---|---|---|
| Love 2005 | 13 | 0 | 1,531 | Yes | United States | Treatment varies: daycare, home visits and both services |
| Harden 2012 | 9 | 0 | 746 | Yes | United States | Weekly home visits, biweekly parent-child group activities |