Cognition and Aging in the USA (CogUSA) 2007-2009 (ICPSR 36053)

Principal Investigator(s): McArdle, John, University of Southern California; Rodgers, Willard, University of Michigan; Willis, Robert, University of Michigan


Cognition and Aging in the USA (CogUSA) is a national longitudinal study of cognition, focused on the age-related changes in cognition across cohorts and on the impact of cognition on key health and economic outcomes. The aim of the CogUSA Study was to evaluate the effectiveness of a variety of tests in assessing cognitive skills on a sample mirroring the Health and Retirement Survey (HRS) (ICPSR 6854). Data were derived in three waves, with each wave utilizing a variety of measures. In Waves 1 and 3, these measures included an adaptive number series test. The Woodcock-Johnson (WJ-III) number series test and the Wechsler Abbreviated Scale of Intelligence (WASI) were used in Wave 2. Waves 1 and 3 were conducted as telephone interviews, while Wave 2 was conducted as an in-person interview. This collection includes indicators of cognitive abilities and functioning as well as a variety of demographic, health, and economic variables. Dataset 1 presents participant demographic information, and Dataset 2 presents scores calculated for the cognitive tests administered to the respondents in each of the three waves.

Access Notes

  • The public-use data files in this collection are available for access by the general public. Access does not require affiliation with an ICPSR member institution.


DS0:  Study-Level Files
DS1:  Demographic Data - Download All Files (5.201 MB)
SAS    SPSS    Stata    R    ASCII    Excel/TSV
ASCII + SAS Setup    SPSS Setup    Stata Setup   
DS2:  Test Score Data - Download All Files (11.093 MB)
SAS    SPSS    Stata    R    ASCII    Excel/TSV
ASCII + SAS Setup    SPSS Setup    Stata Setup   

Study Description


McArdle, John, Willard Rodgers, and Robert Willis. Cognition and Aging in the USA (CogUSA) 2007-2009. ICPSR36053-v1. Ann Arbor, MI: Inter-university Consortium for Political and Social Research [distributor], 2015-04-16.

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This study was funded by:

  • United States Department of Health and Human Services. National Institutes of Health. National Institute on Aging (AG-07407-14)

Scope of Study

Subject Terms:    aging, aging population, cognitive functioning, cognitive impairment, economic behavior, health status, personality assessment

Smallest Geographic Unit:    Census Region

Geographic Coverage:    United States

Time Period:   

  • 2007--2009

Date of Collection:   

  • 2007-05--2007-12
  • 2007-06--2008-01
  • 2008-02--2009-09

Unit of Observation:    Individual

Universe:    Individuals living in the United States, born in 1956 or earlier and their significant others, regardless of age.

Data Type(s):    survey data

Data Collection Notes:

This study is closely related to the Health and Retirement Study (HRS) (ICPSR 6854). Please refer to the file entitled "Original P.I. Documentation" for more details.

The two datasets in this collection can be linked using the variable SAMPID.


Study Purpose:    The goals of CogUSA were: (1) to develop efficient methods of assessing well-recognized components of intelligence and personality that can be administered by surveys using either face-to-face or telephone administration; and (2) to collect multivariate information to better understand how various cognitive abilities change with age.

Study Design:    The CogUSA Study consists of three survey components. Initial contact was established by telephone calls to selected households, and the study began with a 40-minute telephone interview (Wave 1) that replicated the sections of the HRS questionnaire on demography, health and cognition, and added a few brief cognitive tests. This Wave 1 telephone survey was followed as quickly as possible - ideally, within a week - by a 3 hour face-to-face cognitive assessment (Wave 2) of the cognitive abilities of respondents on a large number of different tasks measuring components of "fluid and crystallized intelligence" (after Horn and McArdle, 2007). Respondents were paid $20 for participation in the Wave 1 interview and $60 for the longer Wave 2 interview. Data collection for Wave 1 took place between May and December, 2007. A second telephone survey (Wave 3) took place at a randomized interval of 1 to 24 months following the personal interview (following the Timelag strategy of McArdle and Woodcock, 1997). Randomizations for the Wave 3 telephone interview were done at the respondent, not household, level. Respondents were randomly assigned to one of eight follow-up target dates. Wave 3 telephone interviews began in February, 2008 and continued through September, 2009.

Sample:    The study employs a two-stage RDD sample supplemented with information from a Genesys database to target a sample of households with individuals located in 28 primary sampling units (PSUs) across the nation. Eligible sample members included individuals born in 1956 or earlier and their significant others, regardless of age.

Time Method:    Longitudinal

Weight:    The data are not weighted. However, Dataset 1 includes the weight variable COGWT, which is a respondent-level sample weight based on Wave 2. For more information on weights, please refer to the document entitled "Original P.I. Documentation."

Mode of Data Collection:    cognitive assessment test, face-to-face interview, telephone interview

Response Rates:    47 percent; for more information on response rates across the three waves, please refer to the document entitled "Original P.I. Documentation."

Presence of Common Scales:    Woodcock-Johnson III (WJ-III; Woodcock, McGrew, and Mather, 2001; Woodcock and Mather, 2001) Wechsler Abbreviated Scale of Intelligence (WASI; Wechsler, 1999) Big Five Inventory (BFI; John and Srivastava, 1999)

Extent of Processing:   ICPSR data undergo a confidentiality review and are altered when necessary to limit the risk of disclosure. ICPSR also routinely creates ready-to-go data files along with setups in the major statistical software formats as well as standard codebooks to accompany the data. In addition to these procedures, ICPSR performed the following processing steps for this data collection:

  • Checked for undocumented or out-of-range codes.


Original ICPSR Release:   2015-04-16



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