I've read quite a few adoption blogs where the parents have written about their child's habits and behaviours with respect to what was previously told to them by the child's foster carers. I've seen more than a few comments like "they said he eats anything but we can't get him to even look at a vegetable" (or indeed the other way round - "they said he'd only eat fish fingers but with us he even eats chickpea and lentil soup") or "they said he threw 3-hour tantrums but he's been good as gold here," or "they said she would only fall asleep in front of the tv but we pop her up in her cot and don't hear a peep until morning" or "they said she walks everywhere but we can't get her out of the buggy."
We were a bit surprised at first when we found out that Jack-Jack didn't display any of the behaviours that we saw at home when he was at contact (this was before we found out that this is really common.) We've also seen this phenomenon first hand since Andy moved in. We were told various things about Andy including that he was a terrible eater, that he wouldn't walk more than a few metres at a time, that he wouldn't snack (even that he didn't like biscuits,) that he hates nappy changes and doesn't like taking baths. We haven't seen any of this.
There are many different reasons why a child behaves differently for different carers - perhaps they're not sure how a new carer will react so they hold back from tantrumming and showing strong feelings until they feel more secure, perhaps they are now the only child in the family and are feeling under pressure having 100% of their carers' attention, perhaps they're now one of several siblings and have to learn a different strategy to get attention, perhaps the change of environment and routine has "broken the cycle" of certain habits, perhaps they're in a state of shock or grief from the loss of their previous carers - more often than not we don't know the reason and can only speculate.
I read an article recently called What foster parents wish other people knew which was written collaboratively by a group of foster parents. Although it's written in a rather more forceful tone than we might use, and some of it relates to the foster care system as it is in America rather than the UK, it really struck a chord with us. We've often found ourselves wishing that there was more awareness in the community about fostering and what foster carers do. We've definitely come across some well-meaning but old-fashioned or misguided views on both fostering and adoption, and most people aren't clear on what we can and can't talk about, particularly in front of the children. It's worth a read, even to just open the channels of communication and get people talking about foster care - as it says in the article, becoming a foster carer isn't the only way you can help!