I absolutely love this kind of stuff and found this article from Time magazine really interesting. Have you ever thought about how the birth order of you and your siblings, or your children, has had an effect on everything from intelligence to career success? It's obviously something we have no control over, and somebody has to be first, middle, and last -- but just what does that mean?

Of course this kind of research and the generalized statistics they come up with are hardly across-the-board situations that apply to everybody, but I personally do believe that when you look across a society like ours as a whole you can definitely come up with "more often than not" type generalizations. And it's a little scary to look at some of what they say and see how it fits into each of our families. What patterns does your family follow? Are you typical of your birth order position, or are you the exception to the rule?

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Younger siblings with older brothers may have an increased propensity to become more aggressive with time as opposed to siblings with older sisters, according to a recent study's results.

451 sibling pairs were studied by California researchers (ages nine through 18), and such factors like aggressive behavior, family economic pressures and the hostility of the parents towards the kids were observed.

The conclusions showed that the younger males with older brothers exhibited more aggressive behavior over time, as well as older siblings with younger sisters becoming less aggressive over time. Quite naturally, another conclusion to the study said that parents' hostility also played a role in the aggression development in their kids.

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Are you shorter than your older brother? Chances are it's his fault you're not as tall.

That's according to new research from the University College London, that found younger siblings were generally shorter than their older brothers and sisters.

There's a few different theories as to why this may be the case. One is that, in larger families, resources may be limited, so when you finally arrived there was only so much time, money or love to go around. The other, is that you were adversely affected as a fetus -- as women who have multiple pregnancies are likely to put on weight, which subsequently makes their blood sugar levels poorer and hampers their pregnancy.

But before you start making angry phone calls to your older siblings, blaming them for all your problems, remember that there are plenty of benefits to being in a larger family -- it just turns out that height isn't one of them.

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I think that this is one of the most interesting subjects I've come across in a while. The New England Journal of Medicine recently published this study that suggests people with obese friends are more likely (57% more likely, in fact) to become obese as well. The same can be said for those whose siblings and spouses gain a significant amount of weight, although the results are less significant (40% and 37% respectively).

Basically the research suggests that obesity is socially contagious. If your friend gains weight, you're more likely to as well as are, according to the study, your friends. So what gives? The researchers believe that it's all about ideas and what we all believe is acceptable as far as weight and health are concerned. If your pal becomes obese, your idea of what is considered a healthy body size will change, making you feel it's more acceptable to be heavier.

The good news is that apparently the same goes for losing weight. So if a buddy (or sibling or spouse) begins to eat healthy, exercise regularly and lose weight, you'll get the idea too and be influenced to life a healthier lifestyle as well.

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If you're a women with a twin brother, your chances of conceiving may be reduced by 25%. According to researchers, this is due to the testosterone female twins are exposed to in the womb.

In addition to infertility, there are other interesting side effects -- most notably, that women with male twins seem to be "masculinized." The study found that these women are more likely to exhibit traits, attitudes and behaviors typically associated with men -- which, researchers believe, accounts for the fact that they are 15% less likely to marry than other women.

Of course, it works both ways, so the male twin is also exposed to estrogen -- and previous research has shown that certain physical characteristics, including facial features, can be altered by exposure to hormones of the opposite sex. However, unlike testosterone, both male and female fetuses have similar amounts of estrogen to begin with, so men are less likely to be affected.

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If you have siblings (either gender) but are not close with them, your chance for developing depression later in life is greatly enhanced, according to a new study.

Dr. Robert Waldinger, lead researcher on the study, says that "having a close relationship with even one of your siblings made you less likely to be depressed." Data from 229 men was collected from the teenage years until those same men were in their 50s. Quality of life was then compared to how close each man was with his siblings over that same time period.

It's interesting that the data from this study took 68 years to collect, making it one of the longest studies of adult psychosocial development every done, according to Dr Waldinger.

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Once when I was a kid my brother convinced me to shove a water gun stopper up my nose. Umm... ouch. Despite occasional patches of teasing or trying to get each other in trouble, my brother, sisters, and I got along really well. As adults, my relationship with them is invaluable. I know how big of a support system my siblings and I are for each other, so I found this recent study interesting. New research, published in the American Journal of Psychiatry, shows that having a close relationship with your siblings can reduce your risk of depression.

The study followed 229 men from their teens until they were in their 50s. The consistent predictors of depression risk were family history of depression and/or a poor relationship with siblings. Researchers aren't clear on whether strong sibling relationships help people cope with stressors better or the lack of closeness is a precursor to depression. The study provides an interesting insight on the positive and negative effects on family relationships throughout our lives.

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Growing up with a large number of brothers and sisters may increase your chances of developing stomach cancer. A recent study suggests that early childhood infections -- which are more common in big families -- may contribute to cancer later in life.

After checking blood samples for bacterial infection, researchers discovered that men with certain strains of bacteria in their stomach who also had seven or more siblings were twice as likely to get stomach cancer than men with less than four brothers or sisters. According to Dr. Martin Blaser of New York University, who led the research, "This is a very carefully controlled study that clearly shows that there are factors in early childhood that affect the risk of developing cancer many decades later."

Anyone who's had kids in their house knows that children are bacteria magnets, and it only follows that younger children -- whose immune systems are less-developed -- are more susceptible to contracting infections from their older brothers and sisters. Dr. Blaser also speculates that bacteria transmitted from sibling to sibling is better adapted than that which is transmitted from a non-relative.

Add this to the list of things to blame your older brother or sister for later in life.

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