They're the people we're closest to, and we like to believe we know everything about them - so what happens when a deep-rooted family secret comes out?

Has anyone in your family ever revealed something about themselves that you couldn't ever have imagined to be true? An illegitimate child, an illicit affair or perhaps even a crime or misdemeanor?

There's no doubt that a revelation about a relative can, at times, be enough to tear a family apart. According to psychotherapist Carol Martin-Sperry, there are very few families that don't have secrets. However, she believes that because of the bonds involved, secrets in families are harder to deal with than secrets between friends. 'This is because people assume that they know everything about their family, or that they have a right to know everything,' she says. 'And when they find out they don't, they find it very difficult to deal with. But in fact, people have lives outside of the family. Being related to someone doesn't give you an automatic right to know everything about them.'

'All secrets lie along a scale of how big an effect they'll have, and how shocking they are,' says Martin-Sperry. 'Small secrets usually involve something an individual family member has done, such as taking drugs, being caught shoplifting or getting involved in fraud. Even though other family members can feel very let down and humiliated when they find out these secrets, they are not usually directly affected.'

Bigger secrets are those that have a greater impact on family members - such as affairs, or one person announcing that they are gay. But the secrets that affect an individual member's identity - and which everyone else in the family may know about apart from the person concerned - have the greatest impact of all. Says Martin-Sperry: 'such examples include finding out that your mother had an affair and your father isn't really your father, or finding out you're adopted.'

How a family copes with a revelation depends on their 'coping strategy'. Families with positive coping strategies are those that can talk calmly together, ask questions and accept that while it may take time for things to go back to normal, they're prepared to work hard at being understanding and supportive until they do. 'Families with negative coping strategies can't move past their anger,' says Martin-Sperry. 'They scream, shout and cry until eventually it becomes impossible to talk properly and their relationships are often damaged for good.'

However, even if you've got brilliant coping strategies, it can be very difficult to deal with revelations about a person's identity. 'This is because finding out that your parents aren't who you think they are brings in to question everything about you and can cause a total identity crisis,' says Martin-Sperry. 'It stirs up emotions including shock, denial, anger, sadness and the feeling of being abandoned by your real parents.' For example, in the case of discovering you were adopted, even if you manage to accept and deal with these emotions, in the long term it will be impossible not to feel curious about your real parents, which can cause further damage. Resolving these issues can be a very long and hard process.

Although some families find themselves not speaking after a secret has been let out, it's not a completely bleak picture. 'When I found out I was adopted, I was 19 and all I could think about was finding my own parents. I felt hurt and humiliated that everyone had known about it apart from me,' says Rachel, 30. She adds, 'After a couple of month's hard work, I managed to track down my real family. I discovered that my birth mother was dead, and the family was living in Nottingham. I now see my birth grandparents from time to time, but nothing can replace the bond that all the years with my adoptive parents have given me.' Revelations concerning identity take time to resolve, but that doesn't mean they're not resolvable. Rachel's family understood that. 'I wanted to get to know my genetic relatives, but I still consider my adopted family to be my true family. In fact, I appreciate them more than ever, now that I know just how much they've done for me,' she says.

If you're faced with a family shocker,
'…it's essential you stay calm, keep communicating, don't thrown blame around and don't allow yourself to be swept along by emotion,' says Martin-Sperry. She recommends explaining that you feel hurt, angry and betrayed, but don't scream and shout. Sit down and calmly explain the way you're feeling - don't slam doors or throw punches. Above all, try to look past what is happening around you and remember that if you make an effort, there's a good chance things can get back to normal in time.