---
title: "Stability of general cognitive ability from infancy to adulthood: A combined twin and genomic investigation"
id: "8699"
type: "sample_set"
slug: "snd10136"
published_at: "2026-02-10T21:01:41+00:00"
modified_at: "2026-02-11T19:25:07+00:00"
url: "https://dss.niagads.org/sample-sets/snd10136/"
markdown_url: "https://dss.niagads.org/sample-sets/snd10136.md"
excerpt: "Analyses were based on 1,098 (552 female, 546 male) individuals who completed at least one relevant wave of the ongoing Colorado Longitudinal Twin Study (LTS). This total included 640 individuals who completed measures of cognitive ability in infancy as part..."
---

## Description

Analyses were based on 1,098 (552 female, 546 male) individuals who completed at least one relevant wave of the ongoing Colorado Longitudinal Twin Study (LTS). This total included 640 individuals who completed measures of cognitive ability in infancy as part of the Twin Infant Project (TIP) at age 7 and/or 9 mo of age, 814 individuals who completed up to three assessments between 1 and 2 y of age (*M* = 1.19, *SD* = 0.03; *M* = 1.69, *SD* = 0.04; *M* = 2.04, *SD* = 0.06), 757 individuals who completed the age 3 y assessment (*M* = 3.25, *SD* = 0.16, range 2 to 3), 820 individuals who completed the age 7 y assessment (*M* = 7.42, *SD* = 0.36, range=6 to 8), 813 individuals who completed the age 16 y assessment (*M* = 16.59, *SD* = 0.79, range = 16 to 20), and 684 individuals who completed the assessment at mean age 29 y (*M* = 29.47, *SD* = 1.49, range = 28 to 36) as part of the Colorado Adoption/Twin Study of Lifespan Behavioral Development and Cognitive Aging ([CATSLife](https://dss.niagads.org/cohorts/colorado-adoption-twin-study-of-lifespan-behavioral-development-cognitive-aging-catslife/)
). The TIP was completed in two phases, and a subset of TIP infants also completed some cognitive tests at 5 mo of age, but these data were excluded because they were available on only a small portion of subjects (*n* = 222). Twin analyses included 302 same-sex MZ twin pairs and 241 same-sex DZ twin pairs. 6 additional twin pairs with unknown zygosity were excluded from twin analyses. PGS analyses focused on 693 individuals of European genetic ancestry (from 372 families) with available genetic data. PGS analyses were restricted to match the available discovery GWAS and because samples sizes were too low in non-European genetic ancestry groups to conduct sensitivity analyses, which are expected to have much lower effect sizes when they do not match the ancestry of the discovery sample. All studies were approved by the institutional review board at the University of Colorado Boulder. All individuals completed informed consent at the CATSLife assessment. For earlier waves, parents completed informed consent for their children and children either consented or assented depending on their age.

The current data release includes 1,062 participants, as approximately 4% did not provide consent for broader data sharing beyond the study investigators.

## Cohorts

- [Colorado Adoption/Twin Study of Lifespan behavioral development & cognitive aging (CATSLife)](https://dss.niagads.org/cohorts/colorado-adoption-twin-study-of-lifespan-behavioral-development-cognitive-aging-catslife/)

## Sex

### Total number of samples: 1,062

Female53250.1 %

Male53049.9 %

## Race

### Total number of samples: 1,062

| American Indian/Alaska Native | 9 |
| --- | --- |
| Asian | 2 |
| Native Hawaiian or Other Pacific Islander | 2 |
| Black or African American | 4 |
| White | 911 |
| Other | 52 |
| NA | 82 |

## Ethnicity

### Total number of samples: 1,062

Not Hispanic or Latino

911

85.8%

Hispanic or Latino

79

7.4%

Not Applicable/Not Available

72

6.8%

## Diagnosis

### Total number of samples: 1,062

| NA |  |  |
| --- | --- | --- |
| Other | 1,062 | 100.0% |