''Even though pets may not fully understand or respond verbally, the level of disclosure to pets was no less than to siblings," Cassels continued. "The fact that pets cannot understand or talk back may even be a benefit as it means they are completely non-judgmental."
The study, which was partially funded by WALTHAM Centre for Pet Nutrition, only looked at one age group. It's a fascinating study, though there's certainly more to development than these factors (some of which sibling relationships may very well provide).
The study is garnering interest in part because though pets are wildly common in many countries, they have, as the study's authors write, "received scant empirical attention." It's interesting, but it's just one study. More work will need to be done before you can finally determine that children should be signed up for home school with Professor Fido.