What is intelligence?
‘Legg and Hunter (2007) collected some 70 different definitions of intelligence and summarized them as follows: Intelligence (a) is a property that an individual has as it interacts with its environment or environments, (b) is related to the agent’s ability to succeed or profit with respect to some goal or objective, and (c) depends on how able the agent is to adapt to different objectives or environments. These descriptions of intelligence apply directly to plant behavior and fitness.
‘In the same alphabetical order, (a) wild plants interact with and respond to their environment via competitive and other biotic and abiotic signals; (b) the goal or objective is fitness, with seed number as a fitness proxy—those most successful and therefore most fit provide more offspring; and (c) fitness depends on the skill with which individuals best adapt to their environment throughout their life cycles (McNamara and Houston 1996). Those individual plants that can master the problems of competition and master other biotic and abiotic stresses with greater plasticity, with lower cost, with higher probability, or more rapidly are fitter and, on this basis, are more intelligent.
‘They have a higher probability of survival and a higher probability of collecting the necessary resources to provision seeds. Fitness is, however, inextricably linked to the specific environment in which it operates.
‘There are other descriptions of intelligence that are useful even though they tend to refer to similar kinds of behavior. Intelligence is a capacity for problem-solving, the commonest terminology used by psychologists (Sternberg and Detterman 1986). Those plants that solve their environmental problems—such as the problems described above—more skillfully are fitter than others. Another older alternative is “profiting from experience” (Jennings 1923). This definition involves both learning and the ability to summon up the appropriate memory from the learning experience and use it in future situations to improve fitness. Learning results in the adaptation of the organism. Adaptive modifications improve survival, the accumulation of resources, reproductive potential, and therefore fitness. Finally, adaptively variable behavior during the lifetime of the individual is one I have used (Trewavas 2003) but again is similar to that of profiting from experience. Finally, the word intelligence itself derives from the Latin intelegere, “to choose between.” Many situations arise in the lifetime of the individual that require decisions when there are numerous choices available. Intelligent decisions are those in which the individual selects those choices that improve survival and, in turn, fitness.’
Thanks to new fundraising efforts, I’m going to re-start S P A C E. The Winter 2023/24 series will be a 12-set volume themed, ‘Ecology of the Moment.’