Children's Development and Parental Input: Evidence From the UK Millennium Cohort Study.

In this study, we use the UK Millennium Cohort Study to estimate a dynamic factor model of child development. Our model follows the children from birth until 7 years of age and allows for both cognitive and noncognitive abilities in children. We find a significant self-productivity effect in both cognitive and noncognitive development, as well as some evidence of dynamic dependence across different abilities. The activities that parents carry out with children at home (parental investment) have a significant effect on children's development; we find substantial evidence of two distinct latent parental investment variables with differential effects across the two abilities.

Association of Cognition and Age-Related Hearing Impairment in the English Longitudinal Study of Ageing.

Importance: Evidence has linked age-related hearing impairment (ARHI) with cognitive decline; however, very few studies (none in the United Kingdom) explore this link in large well-characterized groups of community-dwelling individuals. Objective: To investigate the link between ARHI and cognitive decline using a cohort of elderly individuals from the United Kingdom and explore untreated hearing loss and social isolation as potential explanations for the observed link. Design, Setting, and Participants: This cross-sectional analysis of wave 7 (June 2014 through May 2015) of the English Longitudinal Study of Ageing (ELSA) sampled men and women 50 years or older and living in the United Kingdom in a community setting. Those with a diagnosis of dementia, Alzheimer disease, or Parkinson disease or with ear infections and cochlear implants were excluded. Data were analyzed from August 1, 2017, through May 25, 2018. Main Outcomes and Measures: Memory and executive function as measures of cognitive function and hearing acuity derived from the HearCheck screener device (Siemens). Results: Of a cohort of 9666 members in wave 7 of ELSA, 7385 were eligible for analysis after applying exclusion criteria (55.1% women; mean [SD] age, 67.4 [9.4] years). Of these, 3056 (41.4%) had mild hearing loss and 755 (10.2%) had severe hearing loss; 834 (11.3%) used a hearing aid; and 7155 (96.9%) were white. Hearing loss had a negative association with cognition; for those with moderate to severe loss, the score on memory assessment was a full 1 point less (-1.00; 95% CI, -1.24 to -0.76), ceteris paribus, relative to those with no hearing loss. However, this association was seen only in the individuals with untreated hearing loss (ie, those who did not use hearing aids) (-1.16; 95% CI, -1.45 to -0.87). Evidence suggests that social isolation acts as a mediating factor. Conclusions and Relevance: Although hearing loss and cognition are linked, untreated hearing loss drives the association. Social isolation is a mediating factor in the link for those who have untreated hearing loss. Cognitive decline associated with ARHI is probably preventable by early rehabilitation and increased opportunistic screening for the elderly.

Estimating the critical and sensitive periods of investment in early childhood: a methodological note.

The identification of critical periods in early human development requires statistical analyses beyond simple cross tabulation of correlations of observed variables. This paper provides an overview of different quantitative methods available for the statistical analysis of longitudinal data regarding child development, and in particular the identification of critical and sensitive periods for later abilities. It draws heavily on the work on human skill formation developed by the economist James Heckman, which treats ability as a latent variable and explains its formation through the simultaneous estimation of structural equations of investments and achieved abilities across time. We distinguish between two specifications of the ability formation function. One of them (the 'recursive') format explains current ability as a function of the ability and investment at the immediately preceding period. The other (the 'non-recursive') format explains current ability as a function of a series of past investments. In order to fully examine critical and sensitive periods of investments, the non-recursive formulation needs to be used. Furthermore, true abilities of an individual cannot be directly observed: what we observe are the test scores, for example, on reading and writing. We outline an approach, structural equation modelling, that treats actual test scores as measurements of the latent ability variable, and show how it can be used in the recursive and non-recursive formulation. In order to fully examine critical and sensitive periods of investments, we argue that the non-recursive formulation of this structural model is necessary. However, the non-recursive formulation requires more data than the recursive formulation, and to the best of our knowledge, has never been used in the identification of critical and sensitive periods in early childhood development.