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If You Were Born In Summer, This Is What We Know About You

Astrology may be a matter of belief, but there are scientific studies that link birth season to personality and health conditions.

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Your birth month affects your life

Thousands of people check their horoscopes religiously to see what might be in store for them that day, week, month, or even year. And don’t freak out, but your horoscope may have changed recently. But while science doesn’t put much stock in astrology, the field has been uncovering evidence supporting the idea that your birth month or birth season can actually affect your life. Factors like what your mother was eating while she was pregnant with you—e.g. watermelon in summer or pumpkin in fall—and the type of environment she was living in can play a role, but science has yet to explain some traits shared by people with the same birth season. Learn more about what your birth order reveals about your personality.

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You might be big and tall

Your genes are your genes, but a study has shown that babies born in the summer months tend to have a higher birth weight than babies born in other seasons. It might be a hassle getting out and into the world, but it’s better to be a healthy weight rather than frail or weak. The same study that reported this finding also determined that those born in summer months are more likely to be tall—could it be thanks to extra sunshine? It’s not yet clear why, but science has shown that babies born in June and July show the biggest peak in height average. Tall or short, younger or older, these are the 7 proven reasons middle child syndrome isn’t real.

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You have a stronger internal clock

If you have a dog, have you noticed that even without reading a clock, it knows when it’s dinner time? Ever wake up at the same time every day without an alarm clock? This is what’s known as an internal clock, and research suggests summer-born babies tend to have a more robust internal clock than others. Professor of Biological Sciences Douglas McMahon, graduate student Chris Ciarleglio, post-doctoral fellow Karen Gamble and two students at Vanderbilt University performed an experiment on mice that tested how strong their internal clocks were based on what kind of light they were raised in, winter or summer. The study, later published in Nature Neuroscience, showed that mice born and raised in summer light had more accurate internal clocks and regular behavioral patterns than the winter mice babies. In short, the season you’re born into can affect your brain. Here’s what the summer solstice means for your zodiac.

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You have a lower chance of Seasonal Affective Disorder

Not only does the winter environment affect our internal clock, but it can also make us more susceptible to neurological and psychological disorders. Seasonal Affective Disorder is a disorder that’s akin to depression—sometimes severe—due to the changing of the weather and the diminished amount of daylight. Studies have shown that babies born in the summer are less likely to have SAD than winter babies. Like with the mouse experiment mentioned earlier, the theory is that the type and amount of sunlight that summer offers to a newborn makes them better equipped to handle changes in their environment than winter light does. For non-summer babies, make sure you know the ways your birth order can influence your health.

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You have more mood swings

Though there is not yet a detailed explanation for this phenomenon, a study done by the European College of Neuropsychopharmacology has shown that people born in the summer are more likely to be prone to mood swings and shifts in temperament than others. The lead researcher for this study, Assistant Professor Xenia Gonda, reported that the season in which a person is born influences their neurological makeup, including their levels of dopamine and serotonin. These are two chemicals in the brain that help determine levels of happiness or sadness. Dr. Gonda’s research showed that people born in summer are much more prone to mood swings, which means that there is something about being born in summer that influences dopamine and serotonin levels in the brain. This doesn’t mean that summer children are more likely to develop mental disorders like bipolar or schizophrenia later in life—but they might be pretty crabby in the mornings.

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You have a sunny outlook

The same European study that found a link between summer births and mood swings also discovered something else: Summer children are generally more positive-thinking than others—sometimes to an excessive degree. This could be a good thing or a bad thing. Positivity can make you happier, but an excess of it could cause you to overlook or minimize possible pitfalls or obstacles in your path. Aside from your birth month, here’s what your body parts can reveal about your intelligence.

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You could have a greater chance of heart disease and diabetes

Unfortunately, if you were born in the summer, you may have a greater risk of serious medical conditions such as heart disease and diabetes. But it’s not technically the summer that prompts poor health in these areas, it’s any month that doesn’t yield many crops. In this case, it’s about receiving proper nutrition that makes the difference in how healthy you go on to be. If a newborn has access to proper nutrition and healthy food during the early stages of life (aka “the harvest months,” as the study refers to them), then they are more likely to be healthy. Babies who are born in the “lean” months—the less bountiful times of the year, like extreme heat or extreme cold—are more likely to develop heart disease and diabetes later in life.

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You’re less likely to be famous

If you were born in the summer, your dreams of becoming the next Beyonce might already be shot. At least, that’s what one researcher thinks. University of Connecticut professor Mark Hamilton surveyed 300 celebrities in several fields—politics, film, music, sports, and more. From his sample pool, he found that celebrities tend to be born in January and February, not in the summer months. How much stock you want to place in this research is up to you, but as far as Dr. Hamilton is concerned, summer babies don’t have a great shot at being in the limelight. Sorry! (But life is still great, right? Think positive!) Optimism leads to good health.


  • Heliyon: “Season of birth is associated with birth weight, pubertal timing, adult body size and educational attainment: a UK Biobank study”
  • Vanderbilt University: “Season of birth may have long-term effects on personality, study suggests”
  • University of Connecticut: “Celebrities’ Birth Dates Cluster at Certain Points in Year”
  • TIME: “How the Month You Were Born Affects Your Personality, According to Science”

Taylor Markarian
Taylor Markarian is a regular contributor to RD.com covering culture, advice, travel, pets and all things weird and haunted. She is the author of "From the Basement: A History of Emo Music and How It Changed Society," which analyzes the evolution of punk and mental health. She holds a B.A. in Writing, Literature and Publishing from Emerson College.