The Infant Behavior Questionnaire – Revised: psychometric properties at 2 weeks, 3, 6 and 12 months of life

Background: Temperament characteristics are key elements for infants’ development. The Infant Behavior Questionnaire – Revised (IBQ-R) is one of the most used measures to assess temperament in infants aged between 3 and 12 months. Its reliability and factor structure have not yet been examined in infants younger than 3 months. Aims: To analyze the reliability of the IBQ-R at 2 weeks and the IBQ-R factor structure from 2 weeks to 12 months of life. Method: A longitudinal repeated measures design was used. Three hundred mothers completed the IBQ-R when their infants were 2 weeks, and 3, 6 and 12 months. Results: At 2 weeks the proportion of “non-applicable” responses was higher in duration of orienting, high intensity pleasure, approach and smiling and laughter scales. The Cronbach’s alpha for the IBQ-R dimensions ranged between 0.62 and 0.63 and the McDonald’s omega ranged between 0.67 and 0.80, all dimensions exhibited a mean-scale correlation above 0.15, and more than half of the scales revealed a scale-dimension correlation higher than 0.30. The same factor structure was found at 2 weeks, and at 3, 6, and 12 months: surgency/extraversion, p < 0.001, negative affectivity, p < 0.001, and orienting regulation, p = 0.007. Conclusions: The IBQ-R may be applied in the first weeks of life and its factor structure remains stable when applied across different ages throughout infancy.
This study was conducted at Psychology Research Centre (UID/PSI/
01662/2013), University of Minho, and supported by the Portuguese
Foundation for Science and Technology and the Portuguese Ministry of
Education and Science through national funds and co-financed by
FEDER through COMPETE2020 under the PT2020 Partnership Agreement (POCI-01-0145-FEDER-007653).
This research was also supported by FEDER Funds through the Programa Operacional Factores de Competitividade - COMPETE and by National Funds through FCT – Fundação para a Ciência e a Tecnologia
under the project PTDC/SAU/SAP/116738/2010 and individual grants
(SFRH/BD/113005/2015, SFRH/BPD/117597/2016, and SFRH/BD/
115048/2016). EPIUnit is funded by FCT – Fundação para a Ciência e a
Tecnologia, I.P. (UIDB/04750/2020).