Lisa Kudrow can't bear to throw away old faxes and business diaries from the 80s.

The former 'Friends' actress admitted to hoarding old documents, and felt bad about her habit until she appeared on TV show 'Who Do You Think You Are?' - in which she traced her family's past, and found many of her relatives had been victims of the holocaust - and realised even seemingly meaningless papers are part of her family history.

Lisa told "It's the intimate details of these stories that personalise history and adds to the impact. I used to feel bad about holding on to things from my past like my day planners from the '80s, and faxes and stuff.

"I'm not going to feel bad about that anymore because those are all, at some point, potentially important family documents about what I was thinking or feeling at the time.

"It turns out that everything is a clue when you're trying to piece together a life from a few hundred years ago."

The actress, who most recently appeared in the 'Web Therapy' series of internet shorts - originally had aspirations to follow her father into medical school, and said her scientific roots still inform her acting.

She added: "The scientific method done correctly doesn't allow any judgment, no opinions. You can't have it crowded by too much bias. I approach acting the same way. What you learn about your characters is just information, and you're not allowed to judge them."