We ended the last lecture with the observation that habitual inertia resists change. We used the example of accents in speaking to illustrate this. But truthfully, we could have picked any one of a great number of examples. Take the particular side of the road on which one drives. In America we drive on the right side of the road. But in Great Britain, India, Australia and many other former British colonies, people drive on the left side of the road. I experienced the habitual inertia of driving when I visited New Zealand a couple of years ago. I had to be vigilant in making turns especially right turns. I think I did pretty well with that. Though my daughter may disagree and I do admit that I had to stay really focused. I had to use my mind and think about it. But what I did incredibly poorly with were the turn signals and windshield wipers. Because the steering wheel is on the right side they revered the position of the turn signals and windshield wiper switch. On American cars the turn signal is on the left hand side of the steering wheel. On New Zealand cars like British vehicles it's on the right. So almost every time I went to make a turn I activated the windshield wipers instead of the turn signal. The truly amazing thing though is how totally embodied that habit is. It is so embodied that I say I tried to think in preparing this lecture about which side the turn signal is on in my car in the US, I couldn't be sure I actually knew. It seems to be something I never really brought to my consciousness. Okay, so you're probably getting the idea that there is a principle here. I've articulated this principle of inertia in my own research as follows. Culture in motion tends to stay in motion at the same rate unless some other force acts upon it. Although they rarely articulate the principle, anthropologists have long assumed and there would probably be little point am I telling you about this in a class on the power of team culture unless there were other forces at work as well and of course there are. In particular, in addition to the inertial forces, they are the entropic forces. They are typically been discussed in anthropology under the term drift, cultural and linguistic drift. What does that mean? It means that when culture gets copied from one person or one group to the next, it doesn't necessarily get copied precisely. Changes can be introduced. They can be largely random changes, though we'll talk about other kinds later. Lets look at this in terms of the diagram we used earlier to describe the transmission of the cultural element of cutting the end off the roast before baking it. We're using the same diagram here but this time I've put a block arrow beneath the transmission from the mother to her daughter. This indicates the operation of entropic force. I've also put a little slash through the transmission line and an apostrophe after the cultural element, cutting the end off the roast. So the cultural element is not absolutely fixed. It's subject to random change. Incidentally, entropy refers to the tendency towards disorder or randomness. For example, in mass media communication models, there may be static in the signal that is transmitted and the static interferes with the message received. You probably had such an experience with telephone calls when the reception is poor, especially using cellphones. In any case, the result is a learned cultural element that differ somewhat from the transmitted element. In the case of the roads, maybe the result is cutting off more less to the end. The changes can be small but over time, the changes may accumulate. This has been studied in detail for languages. We know that language is always changing, but we can't necessarily perceive the changes. When speakers of the same language become separated into two groups with little or no contact. The languages tend to gradually drift apart, as in this diagram. After a thousand years, it will difficult for speakers of subgroup A to understand speakers of subgroup B. After about 2,000 years the languages will be distinct and largely unintelligible like, say, Spanish and French. Still they retain many similarities which trained linguists are document. Indeed they're able to document them up to about 6,000 years of separation.