Response to Affirmative and Negative Binary Statements

A previous experiment showed consistent and significant differences in the times taken to complete true affirmative, false affirmative, true negative and false negative statements in relation to given situations. In that task only one pattern of stimuli could have made an affirmative true and a negative false, but more than one could have made an affirmative false and a negative true. The present investigation equates the specificity of all statements, and hence eliminates the disjunctive implication of false affirmatives and true negatives by utilizing the mutually exclusive classes of odd and even numbers as material. Two tasks were used, ( a ) ‘verification’, i.e. determining whether a statement about a number is true or false, and ( b ) ‘construction’, i.e. stating a number to make a statement either true or false. In both tasks the form of a statement (affirmative or negative) was significant at the 0·001 level at the end of practice. In the construction task the truth value of a statement (true or false) was also significant at the 0·001 level, but in the verification task it was not significant. These results were obtained from two groups who performed the tasks in a different order. The cognitive processes involved in the tasks are discussed.