Raj Ganatra
Registered Member
Hi,
Recently I read “Race, Evolution and Behavior” by J. Philippe Rushton, 3rd Ed., see http://www.ssc.uwo.ca/psychology/faculty/rushton_pubs.htm and http://www.harbornet.com/folks/theedrich/JP_Rushton/Race.htm In addition, I decided that there were some interesting ideas I would like to expose readers here to, as well as discuss.
In chapter 10 of this book, he goes into what evolutionary biologists call life history theory. This theory is a way that biologists theorize what sort of adaptations different species, or sub-species as in races, make to adapt to various environmental stimuli.
In his book, he details how the three major racial groups have various genotypic, phenotypic and behavioral differences. Some major examples would be brain size and IQ scores (with a correlation between the two as larger brains equals more neurons), gamete production (sperm cells and eggs), hormonal differences (testosterone production for example) and what I will mostly touch on here: reproductive strategies.
Reproductive strategies can be classified into two major types: r and k strategies. Species which practice r-strategies usually emphasize gamete production, mating behavior, low parental care, and high reproductive rates. Species, which practice k-strategies, conversely emphasize high parental care, lower reproductive rates, resource acquisition and a higher degree of social complexity. The k-strategy requires a more complex nervous system as well as larger brains than the primarily r-strategist species do.
In nature, we can see the difference between extreme cases of r and k strategist species. For example, an oyster can produce 500 million eggs a year, while the great apes can reproduce only one infant every 5 or 6 years. Thus, the oyster will have reproduced itself 2500 million times, by the time a great ape will have reproduced itself once. The oyster will not spend any time “parenting” over its offspring, while the great ape will put much time and energy into nurturing their offspring.
While primates in general are the most k-strategist of all of the species, there still remain differences between them. For example, a lemur is more r-strategist than a gorilla. In fact, going across the primate spectrum, research has shown that primates become more k-strategist with increasing brain size, with a correlation of .98.
While humans are primarily k-selected, again differences appear in sub-groups like races as they did within species. As the increased brain size in primates is indicative of k-strategist over r-strategist species, brain size in racial groups also shows a correlation between increased brain size and k-strategist reproductive strategies.
Different means of measuring brain size have been used to gain the average brain size of the three main racial groups that anthropologists usually classify. The methods involve measuring the skull size and estimating brain size, volume displacement of skulls( I.e. filling up an empty skull with a substance and measuring the volume of the skull), autopsy measurements, and more recently, (and the most effective form) MRI. No matter what methods used, the results consistently come out as Mongoloids and Caucasoids both having larger brain sizes than Negroids, with Mongoloids having a slightly larger brain size than Caucasoids who in turn, have much larger brains than Negroids. The mean listed for all of the measurements, to give you an example of the differences of brain size are: Mongoloids 1,364 cm^3, Caucasoids 1,347 cm^3 and Negroids 1,267 cm^3.
The phenotypic, genotypic and behavioral differences between the races are a result of adaptation to environmental stimuli. So what kind of environmental stimuli are responsible for the adaptation of r vs. k strategies and brain size, and what sort of relation are there between the two?
Rushton and others postulate the Single Origin theory. This theory is that Caucasoid and Mongoloid peoples dispersed out of Africa about 100,000 years ago and migrated to the colder, northern environments, while the Negroid peoples remained in Africa in their warmer environment. About 41,000 years ago, there was a split between Mongoloid and Caucasoid peoples, with the Mongoloid peoples splitting migrating towards and even colder environment than the Caucasoid peoples.
Another theory related to the Single Origin theory is one that I will call the bio-energy theory. The bio-energy theory is that each developing sub-species possess a similar amount of bio-energy that a sub-species will expend to act adapt to their environment.
In colder, northern environments, Whites and Asians had to hunt for their food, provide shelter and put more mental energy into survival and social structure than in the sub-Saharan environments of Africa, where the warm weather and abundance of food required less mental energy to be put into survival, I.e. tool building, constructing shelter, farming, etc. Because of these environmental stimuli, Whites and Asians grew bigger brains to deal with this harsh northern environment. A word that evolutionary biologists used to describe this phenomenon is encephalization. Encephalization is an increase in brain size during the evolution of a species, with no concomitant increase in body-size.
While Whites and Asians expended their respective bio-energy on encephalization as response to their environment, blacks on the other hand, adapted r-survival reproductive strategies and used their bio-energy on reproductive efforts. In his book, Rushton details how blacks have higher intercourse frequencies than Whites, who in turn have higher ones than Asians, have a higher developmental precocity (age of first intercourse, first pregnancy) and higher primary and secondary characteristics ( genital size, salient voice, muscularity, buttocks, etc.) than Whites and Asians. They also produce more hormones than Whites or Asians and have more permissive attitudes to pre-marital sex than Whites or Asians and have differing biological behavioral control than Whites or Asians (I.e. length of menstrual cycle, periodicity of sexual response, etc.) In fact, all of these behaviors show a correlation with both brain size and r vs. k selection, with Asians being more k selected than Whites who are more k selected than Blacks; with the abovementioned brain sizes: Asians> Whites> Blacks.
Another interesting component of r vs. k reproductive strategies are some of the social system characteristics. R strategists tend to show low social organization and low altruism while k-strategists tend to favor higher social organization and higher altruism.
Raj Ganatra
Recently I read “Race, Evolution and Behavior” by J. Philippe Rushton, 3rd Ed., see http://www.ssc.uwo.ca/psychology/faculty/rushton_pubs.htm and http://www.harbornet.com/folks/theedrich/JP_Rushton/Race.htm In addition, I decided that there were some interesting ideas I would like to expose readers here to, as well as discuss.
In chapter 10 of this book, he goes into what evolutionary biologists call life history theory. This theory is a way that biologists theorize what sort of adaptations different species, or sub-species as in races, make to adapt to various environmental stimuli.
In his book, he details how the three major racial groups have various genotypic, phenotypic and behavioral differences. Some major examples would be brain size and IQ scores (with a correlation between the two as larger brains equals more neurons), gamete production (sperm cells and eggs), hormonal differences (testosterone production for example) and what I will mostly touch on here: reproductive strategies.
Reproductive strategies can be classified into two major types: r and k strategies. Species which practice r-strategies usually emphasize gamete production, mating behavior, low parental care, and high reproductive rates. Species, which practice k-strategies, conversely emphasize high parental care, lower reproductive rates, resource acquisition and a higher degree of social complexity. The k-strategy requires a more complex nervous system as well as larger brains than the primarily r-strategist species do.
In nature, we can see the difference between extreme cases of r and k strategist species. For example, an oyster can produce 500 million eggs a year, while the great apes can reproduce only one infant every 5 or 6 years. Thus, the oyster will have reproduced itself 2500 million times, by the time a great ape will have reproduced itself once. The oyster will not spend any time “parenting” over its offspring, while the great ape will put much time and energy into nurturing their offspring.
While primates in general are the most k-strategist of all of the species, there still remain differences between them. For example, a lemur is more r-strategist than a gorilla. In fact, going across the primate spectrum, research has shown that primates become more k-strategist with increasing brain size, with a correlation of .98.
While humans are primarily k-selected, again differences appear in sub-groups like races as they did within species. As the increased brain size in primates is indicative of k-strategist over r-strategist species, brain size in racial groups also shows a correlation between increased brain size and k-strategist reproductive strategies.
Different means of measuring brain size have been used to gain the average brain size of the three main racial groups that anthropologists usually classify. The methods involve measuring the skull size and estimating brain size, volume displacement of skulls( I.e. filling up an empty skull with a substance and measuring the volume of the skull), autopsy measurements, and more recently, (and the most effective form) MRI. No matter what methods used, the results consistently come out as Mongoloids and Caucasoids both having larger brain sizes than Negroids, with Mongoloids having a slightly larger brain size than Caucasoids who in turn, have much larger brains than Negroids. The mean listed for all of the measurements, to give you an example of the differences of brain size are: Mongoloids 1,364 cm^3, Caucasoids 1,347 cm^3 and Negroids 1,267 cm^3.
The phenotypic, genotypic and behavioral differences between the races are a result of adaptation to environmental stimuli. So what kind of environmental stimuli are responsible for the adaptation of r vs. k strategies and brain size, and what sort of relation are there between the two?
Rushton and others postulate the Single Origin theory. This theory is that Caucasoid and Mongoloid peoples dispersed out of Africa about 100,000 years ago and migrated to the colder, northern environments, while the Negroid peoples remained in Africa in their warmer environment. About 41,000 years ago, there was a split between Mongoloid and Caucasoid peoples, with the Mongoloid peoples splitting migrating towards and even colder environment than the Caucasoid peoples.
Another theory related to the Single Origin theory is one that I will call the bio-energy theory. The bio-energy theory is that each developing sub-species possess a similar amount of bio-energy that a sub-species will expend to act adapt to their environment.
In colder, northern environments, Whites and Asians had to hunt for their food, provide shelter and put more mental energy into survival and social structure than in the sub-Saharan environments of Africa, where the warm weather and abundance of food required less mental energy to be put into survival, I.e. tool building, constructing shelter, farming, etc. Because of these environmental stimuli, Whites and Asians grew bigger brains to deal with this harsh northern environment. A word that evolutionary biologists used to describe this phenomenon is encephalization. Encephalization is an increase in brain size during the evolution of a species, with no concomitant increase in body-size.
While Whites and Asians expended their respective bio-energy on encephalization as response to their environment, blacks on the other hand, adapted r-survival reproductive strategies and used their bio-energy on reproductive efforts. In his book, Rushton details how blacks have higher intercourse frequencies than Whites, who in turn have higher ones than Asians, have a higher developmental precocity (age of first intercourse, first pregnancy) and higher primary and secondary characteristics ( genital size, salient voice, muscularity, buttocks, etc.) than Whites and Asians. They also produce more hormones than Whites or Asians and have more permissive attitudes to pre-marital sex than Whites or Asians and have differing biological behavioral control than Whites or Asians (I.e. length of menstrual cycle, periodicity of sexual response, etc.) In fact, all of these behaviors show a correlation with both brain size and r vs. k selection, with Asians being more k selected than Whites who are more k selected than Blacks; with the abovementioned brain sizes: Asians> Whites> Blacks.
Another interesting component of r vs. k reproductive strategies are some of the social system characteristics. R strategists tend to show low social organization and low altruism while k-strategists tend to favor higher social organization and higher altruism.
Raj Ganatra
