Although the human genome is 99 percent the same from human to human, it is that 1 percent that can have a major impact on our response to diseases, viruses, medications, and toxins. If researchers can uncover the minute genetic details that set each of us apart, biomedical research and treatments can be better customized for each individual.

Ancestry sleuths be forewarned: While researching your family's past can bring rewards, it might also stir up problems in the present.

Uncovering the roots of your family tree can reveal secrets that might cause conflict and widen rifts between your living family members, a new study finds.

The results show that of 224 people who gave details of their experience researching family history, around 30 mentioned conflicts.

The main bad vibes were caused by: uncovering unwelcome information; wanting information from relatives who didn't wish to give it; giving relatives inaccurate information; spending more time researching than with loved ones; and coming into contact with hostile relatives.

The findings come amidst a boon in online ancestry research, unparalleled public access to historical records, and a flood of celebrity genealogy stories, such as those shown on the TV show "Who Do You Think You Are?" said Anne-Marie Kramer, of the University of Warwick, who conducted the study.

"But in investigating their family history, researchers could open up a Pandora's Box of secrets and skeletons, such as finding there are family issues around paternity, illegitimacy or marriage close to birth of children, criminality, health and mental health and previously unknown humble origins," she said.

Kramer presented her work April 9 at the British Sociological Association's annual conference in Glasgow, Scotland.

The plus side

Kramer analyzed responses to questions about family history research put to people taking part in the Mass Observation Project, based at the University of Sussex, in which people volunteer to write about their lives.

Of the replies, 140 were from women and 83 from men (and one gender unknown), ages 16 to 95 and who lived across the United Kingdom. The participants were either researching their family history or had a relative who was carrying out research.

In most cases people wrote positively about their experience. They enjoyed making discoveries, investigating family myths and mysteries, and bringing their ancestors to life in a sense by finding details of their lives. In some cases, the research could help mend rifts in families.

One 56-year-old woman wrote: "It's great to be able to pass on memories of family members no longer with us, and to learn more about the life they would have had. I think it helps you to feel connected – and also to do honor to people who are no longer with us."

Accounts of annoyance

However, not all experiences were entirely positive. Some participants expressed frustration with ancestry "detectives" forgetting the living.

A 31-year-old man wrote: "It is something of an annoyance to my mother that her own sister can travel to [places abroad] to speak to a distant cousin she never knew existed but cannot get on a train to come and see her own sister as it is deemed too far. Such is family life: spoonfuls of love but bubbling beneath lots of grudges, bruised feelings and massive chips on shoulders."

Others stumbled upon unwelcomed information.

One 70-year-old woman wrote: "The fact that my grandmother was pregnant when she was married and that my parents were also in the same situation before I was born were matters that some felt were better not revealed. For some this information was unwelcome and an elderly cousin accused me of uncovering secrets that were best left hidden."

And some felt pestered by unsolicited requests from long lost relatives.

A 67-year-old woman wrote: "About 40 years ago a male cousin on my mother's side, whom I had never met, got in touch having been given my address by the cousin I'm friendly with. He was, it seems, compiling a family tree. My cousin had given him details of myself and my three marriages and he wanted further details of my husbands and former husbands. What cheek, I thought and how intrusive."

Kramer said the growing popularity in ancestry research has been under-studied, and further work is needed to understand the role of family history in people's everyday individual and family lives, as well as to figure out why they are so compelled to explore their family history.