Lately I've been noticing the spread of a meme regarding "Dunbar's Number" of 150 that I believe is misunderstanding of his ideas.The Science of Dunbar's Number
Dunbar is an anthropologist at the University College of London, who wrote a paper on Co-Evolution Of Neocortex Size, Group Size And Language In Humans where he hypothesizes:
Dunbar supports this hypothesis through studies by a number of field anthropologists. These studies measure the group size of a variety of different primates; Dunbar then correlate those group sizes to the brain sizes of the primates to produce a mathematical formula for how the two correspond. Using his formula, which is based on 36 primates, he predicts that 147.8 is the "mean group size" for humans, which matches census data on various village and tribe sizes in many cultures...
... there is a cognitive limit to the number of individuals with whom any one person can maintain stable relationships, that this limit is a direct function of relative neocortex size, and that this in turn limits group size ... the limit imposed by neocortical processing capacity is simply on the number of individuals with whom a stable inter-personal relationship can be maintained.
It seems like every month more research shows the health impact of sedentary lifestyles, and seeing these new studies so prevalently tells me that there is a growing awareness about the importance of posture on overall health and longevity. Last month, I wrote an article, "Stand Up for Wellness," which was published in Chiro Eco, focusing on posture and motion as important factors for health.
This month, in yet another new study, theBritish Journal of Sports Medicine1 reported growing evidence now linking a sedentary lifestyle with an increased risk of premature death from cardiovascular disease, diabetes, and even some cancers.
Their conclusions provided prevention tips, including:... more
July 10, 2013 By
By Dr. Matt Fontaine
In countries where people spend a great deal of time squatting on their heels with their feet flat, there is a much lower incidence of low back pain and degenerative disc disease. The squatting posture separates the interspinous space between vertebrae. Patients with an increased curvature of the lower back (hyperlordosis) should practice this posture until they can squat comfortably for a total of 3 minutes. Typically, the worse someone is at this exercise, the more they need it.
How to do it, the finer points:
Hold on to the doorway jam or the pole of a squat rack or pullup rack. This allows for better balance and you can squat deeper and hold the position.
Reasons Not to Stretch
By GRETCHEN REYNOLDS
Most of us grew up hearing that we should warm up with a stretch. Strike and hold a pose, such as touching your toes, for 30 seconds or more, we were told, and you’ll be looser, stronger and injury-proof.
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