Ray Kurzweil: "Intelligence is the abiity to solve problems with limited resources."
That's easy to understand at the hunter-gatherer level of complexity and in the talk he gives a related example.
How would we define intelligence in terms of today's complex human societal organization? What factors can be observed to determine whether the intelligence level of a human society is increasing or decreasing?
On an individual basis, the education system trains students to independently solve problems (or it used to), but once they leave that training environment and enter the real world the problem solving process becomes different because it is collaborative. Machines match wits with individual humans in contests of Jeopary or chess that replicate the education system testing environment and the human competitors are being outmatched. However, a human society doesn't work the same way as an individual contest due to the variability of individual brains and the ability of those individual brains to collaborate. If we were to model a computer versus human contest based on the way in which societies produce collective intelligence there might be several hundred collaborating computers playing against several hundred collaborating humans.
Likely the highest known and current level of intelligence in terms of human societal organization (or otherwise) is the collaboration of individuals taking part in innovation, problem solving and consensus decision making in a manner which is as unrestricted as practicable (see Hayek quote below). As that process takes place successfully, the complexity of a human society can increase and the intelligence level of a human society can also increase with that higher level of complexity. Though humans would like it to be so, the evolution of complexity has not historically occurred as a linear process. Getting back to Kurzweil's definition of intelligence, and quoting Joseph Tainter:
Jospeph Tainter wrote:Complex societies are problem solving organizations, in which more parts, different kinds of parts, more social differentiation, more inequality, and more kinds of centralization and control emerge as circumstances require.
The Collapse of Complex Societies, page 37.
Jospeh Tainter wrote:Four concepts discussed to this point can lead to an understanding of why complex societies collapse (in other words, plummet to a lower level of complexity, or collective intelligence - these words in parenthesis are not Tainter's). These concepts are:
1. human societies are problem-solving organizations;
2. sociopolitical systems require energy for their maintenance;
3. increased complexity carries with it increased costs per capita; and
4. investment of sociopolitical complexity as a problem-solving response often reaches a point of declining marginal returns.
The Collapse of Complex Societies, page 93.
Hayek wrote:If man is not to do more harm than good in his efforts to improve the social order, he will have to learn that in this, as in all other fields where essential complexity of an organized kind prevails, he cannot acquire the full knowledge which would make mastery of the events possible. He will therefore have to use what knowledge he can achieve, not to shape the results as the craftsman shapes his handiwork, but rather to cultivate a growth by providing the appropriate environment, in the manner in which the gardener does this for his plants. There is danger in the exuberant feeling of ever growing power which the advance of the physical sciences has engendered and which tempts man to try, "dizzy with success", to use a characteristic phrase of early communism, to subject not only our natural but also our human environment to the control of a human will. The recognition of the insuperable limits to his knowledge ought indeed to teach the student of society a lesson of humility which should guard him against becoming an accomplice in men's fatal striving to control society - a striving which makes him not only a tyrant over his fellows, but which may well make him the destroyer of a civilization which no brain has designed but which has grown from the free efforts of millions of individuals.
As societal complexity (and intelligence) increases, maintaining the status quo level of complexity requires investment, ongoing costs, and behavioral controls which have historically led to an eventual partial collapse of the gains in complexity - the proverbial two steps forward and one step back.