Would you know if your partner was lying to you?

I’ve been married for 18 years and truly trust my husband, but haven’t countless women felt this way, only to discover it was all a lie?

Love is a state of deep vulnerability: you place your heart in another’s hands and wait to see what they do with it. And studies show that most of us lie at least once a day. Some lies are harmless (‘yes darling you look great in that shirt’), others are catastrophic, involving affairs, secrets, financial disaster.

Lies, guilt and shame go hand in hand and often we lie because we are afraid of the consequences of truth: of rejection, disapproval, catastrophe. I explore all this in my latest novel, The Other Child, where Tess, a photographer and single mother, falls deeply in love with Greg, an American paediatric heart surgeon, and moves with him a Boston suburb, only to wonder who she has married.

I explore whether deep love can survive a profound lie. Is deceit ever justified? And how do sensible people like Tess find themselves in such situations? But would you know if you were being lied to? Really? Psychological studies show when people lie they can unconsciously give themselves away. Here are five warning signs to look out for:

The Other Child by Lucy Atkins (Quercus, £7.99) is out now. Visit Lucy’s Facebook page or follow her on Twitter @lucyatkins. Buy The Other Child here