Antony Trewavas

Trewavas published “How plants learn” in 1999, then a short note in Nature in 2002, then “Aspects of Plant Intelligence” in 2003¹. The 2003 paper defined intelligence as adaptively variable growth and development during the lifetime of the individual². A later paper restates the definition in terms of behavior and limits itself to behaviors that improve the survival of plants living in the wild³. Behavior there means the total of a plant's responses to a change in signal or stimulus, including tropic changes in growth³.

Rosciglione reports that Trewavas defines intelligence by function, not by the presence of particular anatomical structures⁴. On that view an organism is intelligent to the extent that it perceives, integrates and responds to environmental information. Rosciglione adds that intelligence is usually read in a broad functional sense, while cognition is a more technical term, and that this plurality of definitions helps keep the debate alive⁴. Calvo and Baluška cite Trewavas for the point that plant survival depends on sampling environmental parameters with plant-specific sensory systems⁵.

The 2003 article drew critical reaction at the time¹. Pecere describes a later exchange in which Taiz and co-authors (2019) protested against anthropomorphism in talk of plant learning and feeling, and Calvo and Trewavas (2020) answered that this was circular reasoning⁶. Pecere takes the crux to be how far an analogy with humans can be extended⁶. Trewavas notes that some regard plant intelligence as obvious while for others it remains controversial, and that much remains unsaid³.