In this report we analyzed genetically informative data to investigate within-person change and between-person differences in late-life cognitive abilities as a function of childhood social class. We used data from nine testing occasions spanning 28 y in the Swedish Adoption/Twin Study of Aging and parental social class based on the Swedish socioeconomic index. Cognitive ability included a gene...

Developmental change in children's number-line estimation has been thought to reveal a categorical logarithmic-to-linear shift in mental representations of number. Some have claimed that the broad and rapid change in estimation patterns that occurs with corrective feedback provides strong evidence for this shift. However, quantitative models of proportion judgment may provide a better account o...

In this paper it is argued that existing accounts of mechanisms of cognitive change in joint nroblem solvine: are inadequate for several reasons. In particular explanations based on sociocognitive conflict do not tell us how the resolution of inter individual conflicts leads to cognitive change. It is argued that a more effective approach is to analyse the dialogue processes involved. A model i...

Lay conceptions of personality change and continuity were examined in a sample of 112 undergraduates. Participants rated their personal change over 5 years (past or future), the change they perceived to be normative over 10-year age spans between 15 and 65, their beliefs about whether personality is fixed or malleable (‘‘lay theories’’) and their beliefs about the causes of personality change a...

Prior experience with a cognitive task is often associated with higher performance on a second assessment, and these experience effects can complicate the interpretation of cognitive change. The current study was designed to investigate experience effects by obtaining measures of cognitive performance separated by days and by years. The analyses were based on data from 2017 adults with two long...

Two major challenges facing researchers interested in cognitive change are that measures of change are often not very reliable, and they may reflect effects of prior test experience in addition to the factors of primary interest. One approach to dealing with these problems is to obtain multiple measures of change on parallel versions of the same tests in a measurement burst design. A total of 7...

If the state of polarization of a monochromatic light beam is changed in a cyclical manner, the beam acquires-in addition to the usual dynamic phase-a geometric phase. This geometric or Pancharatnam-Berry phase equals half the solid angle of the contour traced out on the Poincaré sphere. We show that such a geometric interpretation also exists for the Pancharatnam connection, the criterion acco...

The purpose of this study was to determine the effects of a particular psychological stress, exposure to an open-field, on plasma IL-6 activity in rats. Plasma IL-6 activity was 40.6 +/- 7.2 units/ml in control rats, 105 +/- 6.8 units/ml after 30 minutes exposure to an open-field, and 221 +/- 17 units/ml after 60 minutes of exposure (p = 0.0003). There was a positive correlation (r = .71, p = 0...

OBJECTIVES Many analytical methods are not very sensitive to change because of the difficulty of distinguishing short-term fluctuation from the developmental change of primary interest. The current project investigated one possible solution to this problem in the form of a measurement-burst design in which research participants perform several versions of each test at each measurement occasion....