How can scientists and professionals determine what kind of temperament profile a person has?
In the original New York Longitudinal Study, temperament was assessed by interviewing the parent. Descriptions of the infant or child were coded by a trained researcher and scored for each of the nine categories. Interviews could be individualized to fit each family situation, but took over an hour to complete and then had to be scored by hand.
Later, more time-efficient questionnaires were developed by Carey and associates that measured the same temperamental characteristics as the NYLS. These questionnaires were normed and took just 15-20 minutes to complete and about 10-15 minutes to score. In the mid-90's software was developed to scores the questionnaires and reduced scoring time to 2-3 minutes. Software could also perform statistical calculations instantly that would take hours to do by hand, allowing more specific comparisons to be made, such as using standard scores and doing validity checks.
Researchers have also developed other questionnaires, observational laboratory techniques designed to measure temperamental characteristics. Research questionnaires have measured 'basic' temperament dimensions such as sociability and emotionality, rather than the practical ones selected by the NYLS research program. Observational measures of temperament are often employed in laboratory settings but can also be used at home or school. Usually these involve videotaping responses to "challenges' presented to the infant or child. Observations over a number of situations are added together to achieve a reliable 'view ' of the temperamental characteristic being measured.
More recently physiological measures such as heartrate and cortisol levels have been introduced that seem to correlate to temperament-related behaviors. These methods tie temperament to underlying physiology, which helps to strengthen the case for its biological roots.
Studies have shown moderate levels of agreement amongst the various measurement methods: interview, questionnaire and physiological measures and observation. Each method has its own advantages and drawbacks. Today the questionnaire is the method used for practice since it is the least expensive and most time efficient for professionals to use. A complete assessment of temperament by the professional involves a combination of interview, direct observation of the person and the use of a standardized questionnaire. By putting together the information from all three sources (observation, interview and questionnaire) a valid profile of the temperamental characteristics can nearly always be developed and used to help the person deepen their understanding of their own or their child's individuality and behavior. Using temperament-based descriptions, a common frame of reference can be developed between the person and professional, improving understanding and increasing "goodness of fit.
Practitioners may obtain the materials needed for using temperament questionnaires with infants, children and adults by visiting the Resources tab on this site. For more information about research methods and findings, visit the Researchers tab above.