Human attempts to define intelligence are largely motivated by a desire to prove we have more of it – but a look at the world around us suggests a different story

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INTELLIGENCE has enabled humans to reach for the moon, cure disease and generally dominate this small blue dot of a planet. Arriving at a working definition of intelligence still defeats it, however.

It certainly isn’t just IQ. Tests of pattern finding and word matching capture many of the mental skills that correlate with performance in academic exams and in many workplaces. But they fail on other measures such as wisdom, social sensitivity and practical sense. “No single number captures the rich complexity of what it means to be intelligent,” says Rosalind Arden, an intelligence researcher at the London School of Economics.

There are things we can say. Intelligence “reflects a broader and deeper capability for comprehending our surroundings – ‘catching on’, ‘making sense’ of things, or ‘figuring out’ what to do”, is one oft-quoted attempt to define it. It puts the ability to learn from experience and change behaviour accordingly at the heart of a quality called general intelligence.

This isn’t an exclusively human trait: an octopus’s ability to solve puzzles or an antelope’s talent for assessing the most nutritious grasses is also intelligent behaviour. “Intelligence is the capacity to solve problems relevant to that species,” says Arden.

In our unusually big and well-connected brains, general intelligence has morphed into special talents for abstract thinking, detailed forward planning, understanding the minds of others and insight – those “aha!” moments when we connect cause and effect.

But we shouldn’t get blown away by our supposedly superior abilities: we share virtually all our intelligence skills with close animal relatives. “Humans are limited by our size, our evolutionary history,” says Arden. “Actually we have the sort of intelligence …