The ways we Dream: Nature vs Nurture?
Everyone’s experience with dreaming is a little bit different. Typically, my dreams are relatively uneventful and directly correlated with real life, to the point where I rarely remember them until something in my day triggers it. My sleeping partner, on the other hand, often has bizarre dreams that he struggles to tell me about in the morning, and routinely wakes me up in the middle of the night from moving or talking whilst in a dream. This got me thinking — how much of how we dream is environmental, and how much is just biologically unique to us?
If you experience any kind of parasomnia — such as sleepwalking, sleeptalking, enuresis, bruxism, or nightmares — you probably have heard from a family member that it’s something you unfortunately inherited; these are often found to run in families in clinical practice. However, the research done on these genetic links have been few and far between. As we’ve discussed in previous posts in this series, there are a host of risk factors, such as stress, anxiety, and PTSD, that contribute to all sorts of sleep disorders and disturbances.
Dream content and frequency
Researchers recently identified two key genes in mice that are involved in dream control and quantity of REM and non-REM sleep. Essentially, this means that there are direct genetic links, and therefore can be variations, to what we dream and how deeply we sleep.
In our post on the biology of dreaming, we mentioned that long-lasting memories about life experiences are one of the most common themes present in dreams, so we know that what we experience in life definitely has a huge effect on what we dream about.
Nightmares
Not many studies have investigated the genetic links to nightmares, but a study conducted on twins in 1999 found that there is a genetic disposition to nightmares, both in childhood and adulthood. Another study investigating correlations between nightmares in children and various family influences found a correlation with parents who reported frequent nightmares, though the study was not trying to rule out environmental factors that may have been affecting both the parents and children.
We know that nightmares are also a common side effect of PTSD, anxiety, stress, and depression, some of which can be caused by either genetics, medications, or life events. Check out our blog post all about nightmares for more details on these causes!
Sleeptalking and sleepwalking
In 2011 researchers traced sleepwalking to a single chromosome, and found that carrying a defective section of this chromosome makes you a sleepwalker. In addition, someone with this condition has a 50% change of passing it to their children. Another study on the co-occurrence of parasomnias found a strong genetic covariation between sleepwalking and sleeptalking, suggesting that both have direct genetic causes.
Lucid dreaming
There are various techniques you can find online that supposedly anyone can follow to experience lucid dreams. There are also many anecdotal reports that can be found about people naturally discovering lucid dreaming as children, and of people who’s parents experience lucid dreaming as often and naturally as they do. However, no research has yet been published on whether lucid dreaming is something that comes more naturally to some people than others.
Like many things we experience, most sleep disorders and disturbances have both environmental and biological causes. Generally speaking, if you’ve started to experience some kind of sleep disturbance seemingly out-of-the-blue, the first thing you should do is make sure that you’re taking care of your sleep hygiene — if you’re suffering from sleep deprivation, you’re more likely to experience things like nightmares and night terrors. If it’s something that you’ve experienced your whole life, chances are it’s biological — talk to your doctor if it’s disrupting your sleep.
