Topic of Book
Using archeological data from prehistoric technologies, the author uses statistical analysis to compare the rates of change of human cultures compared to biological changes of animals.
It is generally assumed by social scientists that the rate of cultural evolution, particularly technological innovation, is faster than the rate of biological evolution. Until now, however, there have no solid tests of that theory with empirical data. This study is powerful confirmation that cultural evolution can create substantial changes to human societies in the long-run.
- When measured over long time periods, cultures evolve much faster than biological organisms.
- Biological evolution is clearly faster for animals with short life spans, but even when controlling for this factor, cultural evolution is faster.
- The rate of cultural evolution is clearly accelerating. This does not appear to be true of biological evolution.
- Cultural evolution, like biological evolution, feeds on itself. Each increment of change creates more variation, when then accelerates the change.
Important Quotes from Book
Here, I compare rates of change in human technologies to rates of change in animal morphologies. I find that rates of cultural evolution are inversely correlated with the time interval over which they are measured, which is similar to what is known for biological rates. This correlation explains why the pace of cultural evolution appears faster when measured over recent time periods, where time intervals are often shorter.
Controlling for the correlation between rates and time intervals, I show that (1) cultural evolution is faster than biological evolution; (2) this effect holds true even when the generation time of species is controlled for; and (3) culture allows us to evolve over short time scales, which are normally accessible only to short-lived species, while at the same time allowing for us to enjoy the benefits of having a long life history.
Cultural evolution is expected to be faster than biological evolution because of its Lamarckian nature, and because cultural information is transmitted through different routes than genetic information…. Thus, in contrast to biological evolution, which is blind, cultural evolution can be a directed and consequently faster process. The pace of biological evolution is also constrained by the generation time of the species… While cultural evolution can be transmitted from parents to offspring, it is also transmitted obliquely, between non-parents from a previous generation, and horizontally, between contemporaries. This transmission mode gives cultural evolution the potential to spread rapidly in a population, much like an epidemic disease.
This suggests that cultural change, like biological change, is a multiplicative process: the increments of change in a trait increase as the trait becomes larger.
More surprising, however, is the fact that the magnitude of accumulated cultural changes grows at an increasingly faster pace with time, which is more so than the magnitude of accumulated biological change.
Biological rates calculated over a very short time interval… come from species where the life span is counted in months.