Philosophy of Human Nature

Abstract

The Philosophy of Human Nature (PHN) Scale, developed by social psychologist Lawrence S. Wrightsman in 1964, is an extensively validated psychometric instrument designed to assess an individual’s generalized implicit expectations and fundamental beliefs regarding human behavior, morality, autonomy, and psychological functioning. Operating from the premise that interpersonal perceptions and social interactions are largely governed by stable, enduring worldviews concerning the core characteristics of human beings, the PHN operationalizes these lay assumptions into six primary dimensions: Trustworthiness, Altruism, Independence, Strength of Will and Rationality, Complexity of Human Nature, and Variability in Human Nature. The complete instrument consists of an 84-item self-report inventory organized into six 14-item subscales, each balanced with seven positively keyed and seven negatively keyed statements. Respondents rate their level of agreement on a 6-point Likert-type response scale ranging from disagree strongly to agree strongly. Beyond the primary subscales, the instrument provides two higher-order composite indices: Favorableness of Human Nature (summing beliefs regarding human benevolence, morality, and self-determination) and Multiplexity of Human Nature (reflecting the perceived intricacy and inter-individual variation of people). Across decades of empirical research, the PHN has demonstrated robust psychometric properties, including split-half and Cronbach’s alpha internal consistency coefficients typically ranging from .70 to .84 across subscales, and test-retest stabilities exceeding .75 over longitudinal intervals. The scale exhibits robust convergent, discriminant, and criterion validity through established relationships with interpersonal trust, Machiavellianism, locus of control, authoritarianism, and observed prosocial behaviors in experimental bargaining games and civic engagement contexts.

Keywords

Philosophy of Human Nature, PHN Scale, Lawrence Wrightsman, Interpersonal Trust, Altruism, Lay Theories, Social Perception, Attribution Theory, Construct Validity, Psychometrics, Implicit Personality Theory, Favorableness, Multiplexity

Authors

The Philosophy of Human Nature Scale was conceived, developed, and systematically validated by:

• Lawrence S. Wrightsman, Jr., Ph.D. (1931–2019): Emeritus Professor of Psychology at the University of Kansas, Lawrence, Kansas, United States. Dr. Wrightsman completed his doctoral training in social psychology at the University of Minnesota and served on the faculties of George Peabody College for Teachers (now part of Vanderbilt University) and the University of Kansas. A past president of the Society for the Psychological Study of Social Issues (SPSSI; Division 9 of the American Psychological Association), Wrightsman made foundational contributions to legal psychology, interpersonal trust, jury decision-making, and social attitudes.

Purpose

The primary objective of the Philosophy of Human Nature (PHN) Scale is to quantify an individual’s generalized expectancies and lay theories regarding the character, agency, and predictability of other people. In everyday social interactions, human beings rarely operate as completely objective observers; instead, they filter incoming social stimuli through deeply ingrained belief systems regarding what people are fundamentally like. Historically, social and political philosophers such as Thomas Hobbes, Jean-Jacques Rousseau, and John Locke articulated vastly divergent assertions concerning human nature—ranging from inherently selfish, aggressive, and short-sighted to fundamentally cooperative, noble, and rational. Wrightsman recognized that every layperson similarly functions as an intuitive philosopher, holding implicit assumptions that profoundly shape their social perception, cognitive attributions, and behavioral responses.

In clinical, counseling, and organizational settings, assessing an individual’s philosophy of human nature provides crucial diagnostic and prognostic insights:

• Clinical and Psychotherapeutic Applications: Pervasive cynicism, expectations of exploitation, or the conviction that human beings are thoroughly untrustworthy and malevolent frequently underpin severe interpersonal dysfunction, paranoid ideation, generalized anxiety, and personality pathologies. Administering the PHN enables clinicians to identify maladaptive cognitive schemas regarding interpersonal threat, facilitating cognitive restructuring in schemas of basic mistrust or perceived helplessness.
• Organizational and Leadership Dynamics: In industrial and organizational psychology, managerial assumptions about human nature dictate leadership styles, delegation strategies, and organizational climate. As articulated in Douglas McGregor’s seminal distinction between Theory X and Theory Y, managers who perceive employees as inherently lazy, untrustworthy, and irrational rely on punitive surveillance and authoritarian control, whereas managers holding favorable PHN orientations adopt participative, empowering leadership paradigms.
• Legal and Forensic Contexts: Jurors, judges, and law enforcement officers bring foundational philosophies of human nature into the courtroom. Wrightsman’s extensive empirical work demonstrated that juror scores on Trustworthiness, Strength of Will, and Complexity systematically predict attitudes toward criminal sentencing, witness credibility appraisals, interpretations of defendant culpability, and the endorsement of rehabilitative versus retributive justice.
• Research in Social Psychology: The PHN serves as an indispensable tool for modeling interpersonal bargaining (e.g., Prisoner’s Dilemma simulations), bystander intervention, altruistic behavior, political socialization, cross-cultural comparative values, and reactions to institutional authority.

Psychological Construct

The Philosophy of Human Nature construct posits that generalized attitudes toward human nature are multidimensional rather than monolithic. While an individual may believe that human beings are fundamentally honest, they might simultaneously perceive people as easily swayed by group pressure or incapable of understanding their own subconscious motives. Wrightsman conceptualized the PHN construct around six discrete substantive dimensions, which further organize into two overarching second-order domains:

Substantive Dimensions (Favorableness Subscales)

Four subscales evaluate the perceived positive or negative moral and behavioral quality of human nature. Together, they constitute the generalized Favorableness index:

• Trustworthiness (T): The extent to which human beings are perceived as fundamentally honest, moral, truthful, and dependable versus deceitful, opportunistic, and untruthful. High scorers view people as keeping promises, reciprocating fairness, and refraining from cheating even when unmonitored (e.g., returning unearned test points or adhering to ethical codes). Low scorers maintain that individuals only behave honestly out of fear of detection and punishment.
• Altruism (A): The belief that human beings are genuinely benevolent, unselfish, and empathetic, displaying a natural inclination to assist others without calculated self-interest. High scorers endorse the prevalence of “Good Samaritan” impulses and golden-rule reciprocity, whereas low scorers interpret apparent benevolence as calculated posturing, believing individuals are predominantly conceited, self-serving, and ready to exploit vulnerable counterparts.
• Independence (I): The conviction that the average person possesses autonomous agency, inner firmness, and the courage of their convictions to withstand group pressure, conformity demands, and public opinion. Low scorers endorse an “other-directed” conception of human behavior, viewing people as passive conformists who alter their stated beliefs to appease critics or blend into the crowd.
• Strength of Will and Rationality (S): The extent to which people are perceived as possessing cognitive self-insight, rational decision-making capacities, and autonomous self-determination over their life trajectories. High scorers view human beings as masters of their fate who accurately understand their own motivations and reach their goals through sustained effort. Low scorers view human actions as driven by unconscious impulses, fatalistic circumstances, external locus of control, and irrational biases.

Structural Dimensions (Multiplexity Subscales)

Two subscales evaluate the cognitive complexity and structural differentiation attributed to human nature, forming the Multiplexity index:

• Complexity of Human Nature (C): The belief that individual psychological functioning is intricate, layered, deep, and difficult to decipher versus transparent, simple, and easily categorized into superficial typologies. High scorers recognize that human motives are frequently obscure, requiring nuanced examination. Low scorers believe that an individual’s character can be adequately captured by simple labels or brief first impressions.
• Variability in Human Nature (V): The perception that individuals differ substantially from one another in their basic interests, emotional makeup, and personality structures, as well as the degree to which a single individual’s behavior fluctuates across different situational contexts. High scorers view human behavior as highly individualized and context-dependent, whereas low scorers embrace a model of psychological uniformity, assuming all people are fundamentally alike and predictable across situations.

Theoretical Framework

The theoretical architecture of the Philosophy of Human Nature scale integrates foundational paradigms from attribution theory, personal construct psychology, and social learning theory:

Implicit Personality Theories and Social Cognition

Wrightsman built directly upon the concept of implicit personality theories formulated by Solomon Asch and Fritz Heider. Heider’s naive psychology posited that human beings act as intuitive scientists who construct mental models to explain, predict, and control interpersonal events. In forming impressions, individuals do not evaluate traits in isolation; rather, they operate with pre-existing cognitive networks regarding which human qualities naturally co-occur. Wrightsman extended this concept from impressions of specific target persons to broad, systemic beliefs about the entire human species. An individual’s philosophy of human nature constitutes a master schema that shapes how behavioral cues are encoded, what motives are imputed to ambiguous actions, and how future interactions are anticipated.

Personal Construct Theory

Drawing on George Kelly’s Personal Construct Theory, the PHN reflects the foundational bipolar constructs through which individuals construe their experiential world. Kelly argued that psychological processes are channeled by the ways in which people anticipate events. When an individual anticipates that other humans are untrustworthy (Trustworthiness construct) or puppet-like conformists (Independence construct), their behavioral choices—such as defensive hostility, protective withdrawal, or opportunistic exploitation—logically follow from that cognitive construction.

Social Learning Theory and Generalized Expectancies

The PHN operates in close conceptual dialogue with Julian Rotter’s Social Learning Theory, particularly Rotter’s formulations of generalized expectancies and interpersonal trust. Rotter defined interpersonal trust as a generalized expectancy held by an individual that the word, promise, or verbal or written statement of another individual or group can be relied upon. Wrightsman’s operationalization of Trustworthiness mirrors Rotter’s construct but embeds it within an expanded dimensional matrix that simultaneously accounts for altruism, autonomy, willpower, and cognitive complexity.

Philosophical and Sociological Lineage

Sociologically, the PHN incorporates mid-twentieth-century analyses of modern character structures, including David Riesman’s distinction between “inner-directed” and “other-directed” personalities in The Lonely Crowd (reflected in the Independence subscale) and Erich Fromm’s existential critiques of human alienation and automated conformity. Philosophically, it operationalizes centuries of debate between Hobbesian pessimism regarding human depravity and the Enlightenment optimism of human rationality, dignity, and perfectibility.

Validity

Extensive psychometric investigations conducted across university, community, organizational, and forensic samples have accumulated substantial empirical support for the construct, convergent, discriminant, and predictive validity of the PHN Scale:

Convergent and Discriminant Validity

The convergent validity of the PHN subscales has been corroborated via systematic correlations with parallel personality and attitudinal inventories:

• Interpersonal Trust: Wrightsman (1964, 1974) documented strong, statistically significant positive correlations between the PHN Trustworthiness subscale and Rotter’s Interpersonal Trust Scale (ranging from r = .60 to .75), establishing that the PHN accurately captures generalized confidence in social reliability.
• Machiavellianism: Research examining the relationship between the PHN and Christie and Geis’s Mach-IV scale revealed robust negative correlations between Machiavellianism and PHN Favorableness (Trustworthiness r = -.55 to -.68; Altruism r = -.48 to -.62). High Machiavellians consistently view human nature as cynical, exploitative, and weak-willed, validating the PHN’s sensitivity to opportunistic worldviews.
• Authoritarianism and Dogmatism: Significant negative correlations have been identified between PHN Favorableness dimensions and the California F-Scale as well as Rokeach’s Dogmatism Scale. Individuals with authoritarian personalities tend to perceive human nature as untrustworthy, driven by base impulses, and lacking individual agency.
• Locus of Control: The Strength of Will and Rationality subscale correlates moderately with Rotter’s Internal-External Locus of Control scale (r = -.35 to -.45, where low scores indicate internal locus), demonstrating that perceived human agency corresponds with personal feelings of mastery.
• Social Desirability: Correlations between PHN subscales and the Crowne-Marlowe Social Desirability Scale are typically modest (ranging from r = .10 to .28), indicating that the PHN is relatively free from contaminating impression management biases.

Predictive and Behavioral Validity

The PHN has demonstrated substantial predictive utility across experimental and applied settings:

• Experimental Game Theory: In mixed-motive bargaining scenarios such as the Prisoner’s Dilemma, individuals scoring high on Trustworthiness and Altruism exhibit significantly higher frequencies of cooperative opening moves and reciprocal cooperation compared to low scorers, who exhibit preemptive defection.
• Helping and Prosocial Behavior: Studies examining bystander intervention and spontaneous helping behaviors indicate that high scores on Altruism and Trustworthiness predict willingness to assist distressed confederates, even when costs are moderate.
• Juror Decisions: Wrightsman’s legal psychology studies demonstrated that jurors with low PHN Favorableness scores are significantly more prone to convict criminal defendants, favor harsher penal sanctions, and distrust defendant testimony.

Reliability

The PHN Scale exhibits robust and consistent reliability metrics across diverse demographic populations, including collegiate undergraduates, adult community samples, and occupational cohorts:

Internal Consistency

In original split-half reliability evaluations utilizing the Spearman-Brown prophecy formula, Wrightsman (1964) reported split-half coefficients ranging from .70 to .84 across the six subscales:

• Trustworthiness: .76 to .83
• Altruism: .74 to .81
• Independence: .68 to .78
• Strength of Will and Rationality: .70 to .79
• Complexity: .65 to .75
• Variability: .67 to .76

Subsequent investigations employing Cronbach’s alpha have affirmed these figures, with composite Favorableness scale reliability typically exceeding α = .88 and composite Multiplexity reaching α = .78 to .82. The balanced inclusion of seven positively keyed and seven negatively keyed items within each 14-item subscale effectively prevents response acquiescence from inflating internal consistency estimates.

Test-Retest Reliability

Temporal stability assessments have demonstrated that individual philosophies of human nature function as stable personal dispositions over time. In collegiate cohorts evaluated across a three-month test-retest interval, stability coefficients ranged from r = .74 to .85 across subscales. Evaluations extending to six-month and one-year intervals revealed test-retest correlations consistently above .65, confirming that while attitudes toward human nature can evolve in response to major life crises or significant sociopolitical events, they remain remarkably stable cognitive orientations under standard environmental conditions.

Factor Analysis

Extensive factor-analytic evaluations of the PHN have clarified both its primary facet structure and higher-order architecture:

Exploratory Factor Analysis (EFA)

Initial principal components analyses conducted by Wrightsman and subsequent psychometric researchers confirmed that items load consistently onto their designated substantive dimensions. When a six-factor orthogonal (Varimax) rotation is specified, the primary item loadings range from .40 to .72 on their targeted factors, with cross-loadings rarely exceeding .30. The six extracted factors account for approximately 42% to 48% of the total variance across the 84 items, a substantial proportion for broad social-attitude inventories.

Higher-Order Factor Structure

When oblique rotations (e.g., Promax or Oblimin) are applied to examine inter-factor correlations, a distinct second-order hierarchy emerges:

• Factor I: General Favorableness of Human Nature. The Trustworthiness, Altruism, Independence, and Strength of Will/Rationality subscales load heavily on this superordinate dimension (loadings typically ranging from .55 to .82). These subscales intercorrelate moderately (r = .38 to .58), reflecting a coherent, generalized evaluative orientation regarding whether human beings are inherently positive, capable, and benevolent or negative, vulnerable, and malevolent.
• Factor II: Multiplexity / Cognitive Differentiation. The Complexity and Variability subscales load cleanly onto a distinct second-order factor (loadings > .60). The correlation between the Favorableness composite and the Multiplexity composite is negligible to low (r = .05 to .18), confirming that an individual’s evaluation of human moral goodness is structurally orthogonal to their belief regarding whether humans are psychologically complex or variable.

Confirmatory Factor Analysis (CFA)

Modern structural equation modeling and CFA studies comparing single-factor, orthogonal six-factor, and hierarchical two-factor models have consistently confirmed that the hierarchical model—featuring six first-order factors loading onto two higher-order dimensions (Favorableness and Multiplexity)—provides superior fit indices (RMSEA < .06, CFI > .90, SRMR < .07) compared to unidimensional or unconstrained alternatives.

Instrument / Measurement Tool

The complete Philosophy of Human Nature Scale is an 84-item self-administered psychological instrument structured as follows:

• Instrument Name: Philosophy of Human Nature (PHN) Scale
• Author: Lawrence S. Wrightsman, Jr., Ph.D.
• Publication Year: 1964 (revised monographs 1974, 1992)
• Target Population: Adults and adolescents (approx. reading grade level: 8th grade and above)
• Administration Format: Paper-and-pencil questionnaire, computerized survey, or structured online inventory
• Administration Time: Approximately 15 to 25 minutes
• Total Item Count: 84 items
• Dimensional Architecture: 6 primary subscales (14 items each), yielding 2 higher-order composites:
  • Trustworthiness (T): 14 items
  • Altruism (A): 14 items
  • Independence (I): 14 items
  • Strength of Will and Rationality (S): 14 items
  • Complexity of Human Nature (C): 14 items
  • Variability in Human Nature (V): 14 items
• Item Keying Structure: Each 14-item subscale is split equally into 7 positively keyed items (endorsing the presence of the construct) and 7 negatively keyed items (endorsing the antithesis of the construct).
• Response Scale: 6-point Likert-type response format without a neutral midpoint:
  • agree strongly (+3)
  • agree somewhat (+2)
  • agree slightly (+1)
  • disagree slightly (-1)
  • disagree somewhat (-2)
  • disagree strongly (-3)
• Scoring and Transformation Procedures:
  • When scored using the traditional -3 to +3 format, positively keyed items receive values from +3 (agree strongly) to -3 (disagree strongly). Negatively keyed items are reverse-scored by multiplying the response value by -1 (such that agreeing strongly with a negative item yields -3, and disagreeing strongly yields +3).
  • Alternatively, responses can be converted to a 1-to-6 metric (1 = disagree strongly, 2 = disagree somewhat, 3 = disagree slightly, 4 = agree slightly, 5 = agree somewhat, 6 = agree strongly). For negatively keyed items, reverse scoring follows the formula: Reversed Score = 7 - Raw Score.
  • Each subscale score is computed by summing the 14 keyed item values, producing a subscale score ranging from -42 to +42 (or 14 to 84 under the 1–6 metric).
  • General Favorableness Score: Computed by summing the scores of Trustworthiness + Altruism + Independence + Strength of Will (theoretical range: -168 to +168, or 56 to 336).
  • General Multiplexity Score: Computed by summing the scores of Complexity + Variability (theoretical range: -84 to +84, or 28 to 168).

Permissions & Fee and Test Year

The Philosophy of Human Nature Scale was initially formulated and published in 1964 by Dr. Lawrence S. Wrightsman in Psychological Reports. The scale, along with extensive normative data, was subsequently reproduced in Wrightsman’s authoritative texts (1974, 1992) and in widely utilized reference compendia, such as Robinson, Shaver, and Wrightsman’s Measures of Personality and Social Psychological Attitudes (Academic Press). Under academic fair use conventions, the instrument is accessible without licensing fees for non-commercial educational, scholarly, and clinical research purposes. In commercial assessment environments, standard intellectual property attribution to the author and original publishing outlets is required.

References

• Asch, S. E. (1946). Forming impressions of personality. The Journal of Abnormal and Social Psychology, 41(3), 258–290. https://doi.org/10.1037/h0055756
• Christie, R., & Geis, F. L. (1970). Studies in Machiavellianism. Academic Press. https://doi.org/10.1016/B978-0-12-174450-2.50006-8
• Heider, F. (1958). The Psychology of Interpersonal Relations. John Wiley & Sons. https://doi.org/10.1037/10628-000
• Kelly, G. A. (1955). The Psychology of Personal Constructs. W. W. Norton & Co.
• Riesman, D., Glazer, N., & Denney, R. (1950). The Lonely Crowd: A Study of the Changing American Character. Yale University Press.
• Robinson, J. P., & Shaver, P. R. (1969). Measures of Political Attitudes. Institute for Social Research, University of Michigan.
• Robinson, J. P., Shaver, P. R., & Wrightsman, L. S. (Eds.). (1991). Measures of Personality and Social Psychological Attitudes. Academic Press. https://doi.org/10.1016/C2009-0-03222-0
• Rotter, J. B. (1967). A new scale for the measurement of interpersonal trust. Journal of Personality, 35(4), 651–665. https://doi.org/10.1111/j.1467-6494.1967.tb01454.x
• Wrightsman, L. S. (1964). Measurement of philosophies of human nature. Psychological Reports, 14(3), 743–751. https://doi.org/10.2466/pr0.1964.14.3.743
• Wrightsman, L. S. (1974). Assumptions About Human Nature: A Social-Psychological Approach. Brooks/Cole Publishing Company.
• Wrightsman, L. S. (1992). Assumptions About Human Nature: Implications for Researchers and Practitioners (2nd ed.). SAGE Publications. https://doi.org/10.4135/9781483325606

Items of the Scale