According to a new study[1] , teens who have half-siblings with a different father are much more likely to experiment with drugs and sex before they reach the age of 15 than adolescents who only have full siblings.


The study, carried out by Karen Benjamin Guzzo of Bowling Green State University and Cassandra Dorius of Iowa State University, used data from the National Longitudinal Study of Youth to look at "multi-partnered fertility" (MPF), or having children with multiple partners.


"For children, MPF means having a half-sibling, but it also means, for first-born children, that they usually experienced their biological parents splitting up -- if they were together at all, lived in a single mother household for some time, experienced their mother finding a new partner at least once and perhaps lived with a stepfather, and finally experienced their mother having a baby with a new partner," Guzzo said in a press release[2] .


The researchers found that children who have a half-sibling with a different dad are about 65 percent more likely to have used some form of illegal drugs, including marijuana, uppers, inhalants, cocaine, crack, hallucinogens or sedatives before their 15th birthday than kids with only full siblings. These teens are also 2.5 times more likely to have sex by the time they reach the age of 15.


"We find that first-born adolescents with half-siblings with the same mother but a different father do have less favorable outcomes compared to their peers with only full siblings, even after accounting for the mother's background characteristics, socioeconomic factors the child experienced growing up, and family instability and structure," Guzzo said.


This isn't the first study to look at how familial instability influences a child's development. A University of Virginia study in July 2013[3] found that infants who spent at least one night a week apart from their mothers due to joint custody formed less secure attachments to them. And a recent study in the Journal of Consumer Affairs[4] found that compulsive buying behavior in adulthood can be a result of parental divorce in childhood.


Click through the slideshow below to see more significant divorce findings.



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  • Couples Who Share Housework Are More Likely To Divorce


    Splitting chores could lead to divorce? According to a Norwegian study released in August 2012, the divorce rate among couples who divvy up household chores is <a href="http://www.huffingtonpost.com/2012/09/28/divorce-rates-couples-who_n_1923623.html">roughly 50 percent higher </a>than for those in which the wife handles the housework.

    So does that mean couples shouldn't split the chores equally? Not necessarily. Researchers say that the higher divorce rate has more to do with "modern" values and attitudes -- such as viewing marriage as less sacred -- rather than a <a href="http://www.huffingtonpost.com/2012/09/28/divorce-rates-couples-who_n_1923623.html" target="_hplink">cause-and-effect relationship</a>.




  • Divorce Could Be In A Woman's Genes


    In February 2012, Swedish scientists released a study suggesting that a specific <a href="http://www.huffingtonpost.com/2012/02/27/karolinska-institute-divorce-gene_n_1304899.html">gene may explain why some women have a hard time committing</a>, or staying committed, should they marry.

    The researchers found that women who possessed a variation of the oxytocin receptor gene known as A-allele were <a href="http://www.huffingtonpost.com/2012/02/27/karolinska-institute-divorce-gene_n_1304899.html">less likely to get married</a> due to difficulty bonding with other people. Those with the gene who did marry were 50 percent more likely to report "marital crisis or threat of divorce."




  • A Close Relationship With Your In-Laws May Change Your Divorce Odds


    In November 2012, a 26-year longitudinal study released by the University of Michigan found that when a husband reported having a close relationship with his wife's parents, the couple's risk of <a href="http://www.huffingtonpost.com/2012/11/27/in-laws-and-marriage_n_2199637.html">divorce decreased by 20 percent</a>. On the other hand, when a wife reported having a close relationship with her husband's parents, the couple's <a href="http://www.huffingtonpost.com/2012/11/27/in-laws-and-marriage_n_2199637.html">risk of divorce <em>increased </em>by 20 percent</a>.

    Why the difference? Researcher <a href="http://online.wsj.com/article/SB10001424127887323713104578137222992767676.html">Terry Orbuch told the Wall Street Journal</a> that she believes that many wives eventually view their in-laws' input as meddlesome, while husbands tend to take their in-laws' actions less personally.




  • Men Are More Likely Than Women To Turn To Drinking After A Split


    A University of Cincinnati study <a href="http://abcnews.go.com/blogs/health/2012/08/20/marriage-means-more-drinking-for-women-less-for-men/">presented in August 2012</a> found that<a href="http://www.huffingtonpost.com/2012/08/20/drinking-after-divorce_n_1812235.html"> men are more likely than women to turn to drinking</a> after divorce.

    "Marriage and divorce have different consequences for men's and women's alcohol use,"<a href="http://consumer.healthday.com/Article.asp?AID=667788&loc=interstitialskip"> study author Corinne Reczek told Health Day.</a> "For men, it's tempered by being married and exacerbated by being divorced."

    Additionally, the study suggested that <a href="http://www.eurekalert.org/pub_releases/2012-08/asa-set_1081312.php">married women drink more</a> than their divorced or widowed friends -- partly because they lived with men who had higher levels of alcohol use.




  • Cold Feet Warn Of Marital Trouble Ahead


    Don't ignore those pre-wedding jitters: they may warn of marital trouble ahead, according to a <a href="http://www.huffingtonpost.com/justin-lavner/do-cold-feet-warn-of-mari_b_1910770.html">UCLA study published in the Journal of Family Psychology</a> in September 2012. Researchers asked 232 newlyweds in their first marriages whether they had <a href="http://www.huffingtonpost.com/justin-lavner/do-cold-feet-warn-of-mari_b_1910770.html">"ever been uncertain or hesitant about getting married"</a> after they got engaged. The research team followed up with the couples every six months for the first four years of their marriages.

    In a <a href="http://www.huffingtonpost.com/justin-lavner/do-cold-feet-warn-of-mari_b_1910770.html">HuffPost blog</a>, one of the researchers, Justin Lavner, explained that premarital doubts predicted divorce rates four years later, especially when the doubtful partner was the wife. <a href="http://www.huffingtonpost.com/justin-lavner/do-cold-feet-warn-of-mari_b_1910770.html">According to Lavner,</a> "19 percent of couples in which wives had doubts were divorced four years later, but only 8 percent of couples in which wives did not have doubts ended up divorced. Husbands' doubts did not significantly predict divorce, although divorce rates were somewhat higher among husbands with doubts (14 percent) than husbands without doubts (9 percent)."




  • Men Who Cheat Are More Likely To Have Heart Attacks


    According to a study released in May 2012 by the University of Florence, “sudden coital death” is more common when a <a href="http://www.huffingtonpost.com/2012/05/23/cheating-study_n_1540465.html">man is engaging in extramarital sex </a>in an unfamiliar setting than when he's having sex with his spouse at home. The researchers found that infidelity outside the home was associated with <a href="http://www.huffingtonpost.com/2012/05/23/cheating-study_n_1540465.html">"a higher risk of major cardiovascular event,"</a> including fatal heart attacks. “Extra-martial sex may be hazardous and stressful because the lover is often younger than the primary partner and probably sex occurs more often following excessive drinking and/or eating," researcher <a href="http://www.dailymail.co.uk/health/article-2148426/Its-just-bad-marriage-Cheating-partner-heart-attack.html">Dr. Alessandra Fisher told the Daily Mail</a>. “It is possible that a secret sexual encounter in an unfamiliar setting may significantly increase blood pressure and heart rate, leading to increased oxygen demand.”




  • Moving In Before Marriage No Longer Predicts Divorce


    Living together before marriage is <a href="http://www.huffingtonpost.com/2012/03/22/movein-before-marriage-no_n_1372687.html">no longer a strong predictor of divorce</a>, according to a study released by the Centers for Disease Control and Prevention in early 2012.

    As part of a marriage survey of 22,000 men and women, researchers found that those who were engaged and living together before the wedding were <a href="http://www.huffingtonpost.com/2012/03/22/movein-before-marriage-no_n_1372687.html">about as likely to have marriages that lasted</a> 15 years as couples who hadn't cohabited.

    What about couples who moved in together but weren't engaged? The study found their <a href="http://www.huffingtonpost.com/2012/03/22/movein-before-marriage-no_n_1372687.html">marriages were less likely to survive</a> to the 10- and 15-year mark.




  • Divorce Is Too Expensive For The Poorest Americans


    More couples are opting for long-term marital separations because they <a href="http://www.huffingtonpost.com/2012/08/20/divorce-expensive-americans_n_1811821.html">cannot afford to divorce</a>, according to a study conducted by <a href="http://www.huffingtonpost.com/2012/08/20/divorce-expensive-americans_n_1811821.html">Ohio State University</a> that was published in August 2012. Researchers surveyed 7,272 people between 1979 and 2008. Most people in the study who separated from a spouse reported getting a divorce within three years of separating. But <a href="http://www.eurekalert.org/pub_releases/2012-08/asa-msa081412.php">15 percent of people who separated did not get a divorce within the first 10 years</a> because it was too costly, especially when children were involved.




  • Divorce Hurts Health More At Earlier Ages


    Divorce at a <a href="http://www.huffingtonpost.com/2012/01/30/divorce-study_n_1242553.html">younger age hurts people’s health</a> more than divorce later in life, according to a <a href="http://msutoday.msu.edu/news/2012/divorce-hurts-health-more-at-earlier-ages/">Michigan State University study</a> released in January 2012. Sociologist Hui "Cathy" Liu looked at self-reported health information of <a href="http://msutoday.msu.edu/news/2012/divorce-hurts-health-more-at-earlier-ages/">1,282 participants over the last 15 years</a>, analyzing the difference in well-being between those who remained married over the course of the study and those who divorced. Among the divorced, Liu found that those who split at a younger age <a href="http://msutoday.msu.edu/news/2012/divorce-hurts-health-more-at-earlier-ages/">tended to have more health issues</a> than those who divorced later in life. Liu said the findings suggested <a href="http://msutoday.msu.edu/news/2012/divorce-hurts-health-more-at-earlier-ages/">older people have more coping skills</a> to deal with the stress of divorce.




  • Women Close To Divorcing Tend To Work More Hours


    In November 2012, the European Economic Review released a study that revealed <a href="http://www.dailymail.co.uk/sciencetech/article-2232318/Is-wife-working-late-It-sign-marriage-trouble.html">women who clock an extra 12 minutes per week face a 1 percent increase</a> in the risk of a marital breakdown.

    Why? Lead researcher Berkay Ozcan, PhD, explained that working more hours is <a href="http://www.dailymail.co.uk/sciencetech/article-2232318/Is-wife-working-late-It-sign-marriage-trouble.html" target="_hplink">a "form of insurance"</a> for women when their marriage is on the rocks.

    The study also found that there is <a href="http://www.dailymail.co.uk/sciencetech/article-2232318/Is-wife-working-late-It-sign-marriage-trouble.html" target="_hplink">no strong evidence</a> to suggest men do the same when divorce seems likely.





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