Ego Identity Scale (EIS)

Abstract

The Ego Identity Scale (EIS), developed by John E. Rasmussen in 1964, is a specialized rating instrument designed to empirically investigate Erikson’s theoretical concept of Ego Identity. The scale focuses on the successful resolution of the first six psychosocial crisis stages outlined in Erikson’s comprehensive developmental framework.

The development process began with an extensive pool of 144 potential items, including 136 original statements and 8 items sourced from existing personality tests. Through rigorous item analysis conducted on preliminary forms administered to Navy recruits, the instrument was carefully refined. The final version of the EIS comprises 72 statements, demonstrating strong psychometric properties, particularly high internal consistency reliability, with coefficients reaching .851 using the Spearman-Brown prophecy formula.

Keywords

Ego Identity Scale, Ego Identity, Erikson’s Theory, Psychosocial Development, Identity Diffusion, Personality Assessment, Rating Scale, Self-Concept.

Authors

Rasmussen, John E.

Purpose

The primary purpose of the Ego Identity Scale (EIS) is to provide a quantitative methodology for studying and measuring the psychological construct of Ego Identity, as conceptualized within the framework of Erikson’s stages of psychosocial development.

Specifically, the EIS aims to assess the degree to which an individual has successfully navigated and resolved the challenges inherent in the first six psychosocial crises, which are foundational to establishing a cohesive sense of self and identity and predicting psychosocial effectiveness.

Construct

The scale measures Ego Identity. According to Erikson, ego identity is defined as the conscious sense of self derived from an ongoing process of negotiation between individual capacities and societal expectations. Successful resolution results in a stable identity, while failure can lead to identity diffusion or role confusion.

The 72 items of the EIS are specifically mapped onto the theoretical outcomes of the first six psychosocial stages: Trust vs. Mistrust, Autonomy vs. Shame and Doubt, Initiative vs. Guilt, Industry vs. Inferiority, Identity vs. Role Confusion, and Intimacy vs. Isolation. The scores reflect the individual’s progress toward achieving an integrated, mature identity.

Validity

The validity of the Ego Identity Scale relies strongly on its Content Validity. The instrument’s development was meticulously aligned with the specific theoretical criteria established by Erik Erikson regarding the successful resolution of psychosocial crises, ensuring that the items accurately reflect the theoretical domain of the construct.

To ensure high content fidelity, the statements comprising the scale were subjected to expert review. Two independent judges, highly knowledgeable in Erikson’s developmental theory, unanimously validated the alignment of the items with the intended constructs, confirming that the scale adequately samples the domain of ego identity as defined by the underlying psychological theory.

Reliability

The Ego Identity Scale demonstrated strong internal consistency during its initial validation phase. Reliability was assessed using the split-half method, with the resulting internal consistency estimated by the Spearman-Brown Prophecy Formula, a standard psychometric technique used to estimate the reliability of the full-length test.

The resulting correlation coefficients were highly favorable, yielding values of .849 and .851. These statistics indicate that the various items within the 72-statement final scale are highly intercorrelated and consistently measure the same underlying construct, suggesting a robust level of internal reliability for the instrument when applied to similar populations.

Factor Analysis

The original published documentation regarding the development and validation of the Ego Identity Scale (EIS) in 1964 does not explicitly indicate that a formal Factor Analysis was conducted or reported. Therefore, information concerning the empirical underlying factor structure or dimensionality of the 72 items is not available in the foundational source material by Rasmussen.

While the scale is theoretically structured based on six distinct psychosocial stages, the empirical confirmation of these sub-dimensions through techniques like Exploratory or Confirmatory Factor Analysis remains undocumented in the initial study. Subsequent research using the EIS or revised versions may have explored its factorial structure, but this information is absent from the original 1964 publication.

Instrument

Test Type: Rating Scale

Format: Responses are captured using a dichotomous agree-disagree format, requiring the respondent to indicate their agreement or disagreement with each of the 72 statements.

Language Available: English

Population Group: Human

Age Group: The initial sample focused on young adult recruits, suggesting suitability for late adolescence and early adulthood, aligning with the Identity vs. Role Confusion stage.

Population Details: The scale was standardized and initially tested on a specific sample of Recruits at a U.S. Naval Training Center.

Test Methodology: The instrument is administered via Paper format, requiring self-report responses.

Keywords

Personality Development, Psychosocial Effectiveness, John E. Rasmussen, Identity Status, Military Sample, Assessment Instrument, Spearman-Brown.

Authors

Author ORCID Identifier: Not provided in source documentation.

Affiliation Email addresses: Not provided in source documentation.

Correspondence Address: Not provided in source documentation.

Permissions & Fee and Test Year

The Ego Identity Scale was initially published in 1964. Regarding usage and distribution rights, permission must be obtained by contacting the original publisher (Psychological Reports) of the academic journal in which the scale was introduced. The scale is classified as non-commercial and does not require a fee for its use, though access to the full test items may be restricted by the publisher or author.

Reference’s

• Rasmussen, J. E. (1964). Relationship of ego identity to psychosocial effectiveness. Psychological Reports, 15(3), 815–825. The full article is available via DOI: https://doi.org/10.2466/pr0.1964.15.3.815

Items of the Ego Identity Scale (EIS)

IMPORTANT: The following scale items must be preserved in their original language and must not be changed in any way.

Test items for the Ego Identity Scale are not available in this source. The total scale consists of 72 statements. Users interested in obtaining the full set of testing materials are advised to contact the original author, John E. Rasmussen, or the journal publisher directly, as the items are proprietary.