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Grammatical Reasoning

Test type: Reasoning

If A is bigger than B but smaller than C, which letter is the biggest?

How good is your ability to reason? Try this test to find out.

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About this test

Try this 20,000 leagues under the sea...

This test measures how well your brain can reason about the relationships among different letters based on deductions from grammatical statements. The difficulty of each problem depends on the grammatical statement presented; those with simple active sentences (A follows B) are more easily understood than those with passive or negative statements (A does not precede B), which require complex reasoning to solve.

This task is an adaptation of the Grammatical Reasoning Test which was developed in 1968 by Alan Baddeley, the previous Director of the MRC Cognition and Brain Sciences Unit (then known as the MRC Applied Psychology Unit). The original task was developed to measure mental capabilities of divers suffering from nitrogen narcosis (an altered mental state akin to drunkenness that develops when divers breathe compressed air at extreme depths). Cognitive impairments were observed at depths of around 30 meters. Interestingly these impairments were more severe when divers were actually at sea compared to when they were in a compression tank, a possible result of increased anxiety in the 'real world' situation (Baddeley & Flemming 1967; Baddeley et al 1968).


-Baddeley, A.D. (1968). A three-minute reasoning test based on grammatical transformation. Psychometric science: 10, 341-342.
-Baddeley, A.D., and Flemming, N.C. (1967). The efficiency of divers breathing oxy-helium. Ergonomics: 10 (3):311-9.
-Baddeley, A.D., de Figueredo, J.W., Hawkswell Curtis, J.W and Williams, A.N. (1968).Nitrogen Narcosis and Performance Under Water. Ergonomics: 11(2),157-164.

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