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Gillian Stamp's Mode of Thinking, Career Path Appreciation, and Jaques & Cason's Human Capability — A Literature Review

A corrected review of Gillian Stamp's Mode of Thinking construct within the Career Path Appreciation method, distinguished from Elliott Jaques and Kathryn Cason's four Types of Mental Processing, and situated within Elliott Jaques's Stratified Systems Theory.

Published: September 14, 2025 · Updated: August 17, 2026

Excerpt

Gillian Stamp’s Mode of Thinking is a construct within her Career Path Appreciation (CPA) method: a person’s projected future potential level of work decision-making capability, read off Elliott Jaques’s array of growth curves. It is often confused with Jaques and Cason’s four Types of Mental Processing — declarative, cumulative, serial, parallel — which are a different construct entirely. This review restores the correct distinction, situates both frameworks inside Stratified Systems Theory, and documents the CPA’s structure, its evidence base, and its critiques.

Introduction and Academic Context
Two Constructs, One Confusion
Stratified Systems Theory as the Shared Foundation
Stamp’s Side — Career Path Appreciation and Modes
Jaques and Cason’s Side — Human Capability and Types of Mental Processing
How the Two Sides Fit Together
Application, Evidence, and Predictive Validity
Comparisons with Other Cognitive and Decision-Making Models
Critiques, Validations, and Adaptations
Conclusion
References

Introduction and Academic Context

Gillian Stamp developed the Career Path Appreciation (CPA) at the Brunel Institute of Organisation and Social Studies (BIOSS) in the late 1970s, naming the refined procedure by 1982 (Jaques & Stamp, 1990, ARI Technical Report ADA226910). CPA is a structured interview that reads a person’s current level of work decision-making capability and, against Elliott Jaques’s empirically derived growth curves, projects their future potential capability. Stamp used the word mode to name that projected future potential — a specific technical term inside CPA, not a general label for “ways of thinking” (Oosthuizen, Coetzee & Kruger, 2014, SAJIP; Cognadev on SST).

A separate body of work by Elliott Jaques and Kathryn Cason — published as Human Capability in 1994 — identified four, and only four, distinct patterns of mental processing that people use when engrossed in problem solving: declarative, cumulative, serial, and parallel. These four types recur across four orders of information complexity, generating a recursive matrix that maps onto Jaques’s seven strata of work (Global Organization Design Society summary of Human Capability; Jaques, Requisite Organization, via Perlego; Wikipedia summary of Jaques).

Much of the practitioner and secondary literature blurs these two constructs and labels the four processing types as “Stamp’s four Modes of Thinking.” That is inaccurate. This review keeps the two sides distinct and shows precisely where and how they connect.

Two Constructs, One Confusion

The single most important correction is terminological. Six constructs get routinely confused; keeping them named and counted correctly is most of the work.

Mode (in CPA) — Stamp and Jaques. Seven bands, I–VII (Jaques’s 1961 array collapsed to eight in the earliest formulation). A growth-curve band: each band groups all individual maturation curves that reach their maximum at the same level of work.

Types of Mental Processing — Jaques and Cason (1994). Four types. Declarative, cumulative (also “accumulative”), serial, parallel. These describe the shape of reasoning, not seniority.

Orders of Information Complexity — Jaques and Cason (1994). Four orders. Concrete verbal, symbolic verbal, abstract conceptual, universal.

Full Type × Order matrix — Jaques and Cason (1994). Sixteen cells. Each of the four types recurs at each of the four orders (for example, B3 = symbolic serial; C2 = conceptual cumulative).

Levels of Work, or Strata (SST) — Elliott Jaques. Seven strata, occasionally extended to eight. Organizational strata differentiated by time span of discretion.

Decision-making Styles (in CPA) — Gillian Stamp. Five styles, A through E. The person’s preferred approach to gathering and arranging information — not modes, and not processing types.

The ARI report co-authored by Jaques and Stamp is explicit: “In 1961 Jaques summarised the array of progression curves into eight modes to reflect the hypothesis that capacity is multi-modally distributed and that the boundaries between capacity groups represent complete discontinuities” (Jaques & Stamp, 1990, ADA226910). CPA’s practical read is against the seven-band form (I–VII) that maps directly onto the seven strata of Stratified Systems Theory (University of Pretoria dissertation on CPA).

Stratified Systems Theory as the Shared Foundation

Elliott Jaques’s Stratified Systems Theory (SST) proposes that work in organizations is naturally stratified into levels of increasing complexity, each with a longer time span of discretion — the maximum time a role holder is expected to exercise judgment without direct review (Talking About Organizations podcast summary; Ninety.io explainer). Real managerial boundaries recur at time spans of 3 months, 1 year, 2 years, 5 years, 10 years, and 20 years, identified across more than 100 of Jaques’s studies (Cognadev).

The seven strata as presented in the ARI report and in BIOSS materials, each named by its time span of discretion and its characteristic work:

Stratum I — up to 3 months. Direct operating tasks. Illustrative civilian role: shop-floor operator.
Stratum II — 3 months to 1 year. Direct operating methods; first-line supervision. Section supervisor.
Stratum III — 1 to 2 years. Direct operating systems. Unit or department manager.
Stratum IV — 2 to 5 years. Alternative operating systems; general management. General manager.
Stratum V — 5 to 10 years. Complex systems within a business unit. Subsidiary head or SBU leader.
Stratum VI — 10 to 20 years. Direct deployment of complex systems. Group executive.
Stratum VII — 20 to 50 years. Strategic design of complex systems. Corporation CEO or board.

Sources: Jaques & Stamp, 1990 (ADA226910); Bioss on levels of work.

Both Stamp’s CPA and Jaques & Cason’s Human Capability model plug into this seven-stratum spine — but they measure different things.

Stamp’s Side — Career Path Appreciation and Modes

What CPA measures

CPA is a semi-structured, one-on-one interview, typically about two hours, that yields three readings (Oosthuizen et al., 2014, SAJIP; Cognadev on CPA; University of Pretoria dissertation):

Current Level of Capability (CLC) — the level of work complexity the person is comfortable engaging with today, scored I to VII.
Mode — the person’s predicted future potential level of work decision-making capability, read off Jaques’s growth curves using CLC and the person’s current age.
Style — the person’s preferred approach to gathering and arranging information; one of five types (A, B, C, D, E) described below.

The three interview components

The CPA interview has three parts (Cognadev; Jaques & Stamp, 1990):

Phrase cards — nine sets of six cards; the interviewee selects those that describe their approach to work and elaborates on the choice.
Symbols — a geometric-symbol sorting task in which the person discovers the rule; used to read stylistic preference. In the original administration this used 162 cards (later refined to 170), with feedback given on three of four display cards, requiring ten consecutive correct sorts.
Work history — a chronological description of past roles, challenges, and time spans, used to triangulate current capability.

The interviewer does not score the material numerically; content is interpreted against the level-of-work model and the growth-curve array (Bioss / Stamp, “The Individual, the Organisation and the Path to Mutual Appreciation”).

The Modes — seven bands, not four types

In CPA, a Mode is a growth-curve band: the group of all individual maturation curves that reach their maximum at a given level of work. The University of Pretoria dissertation on CPA shows the growth-curve figure with seven bands, labelled I through VII. Each carries a value-adding theme used in the Matrix of Working Relationships:

Mode I — Quality. Touch-and-feel capability. Typical role: front-line operator or semi-skilled worker.
Mode II — Service. Accumulation of information. Supervisor.
Mode III — Practice. Connecting. Department or line manager.
Mode IV — Strategic Development. Modelling. General manager.
Mode V — Strategic Intent. Weaving — creating links between issues and events. Managing director or SBU head.
Mode VI — Corporate Citizenship. Revealing — extending curiosity. Executive vice president.
Mode VII — Prescience. Shaping not-yet-given contexts. Corporation leader or board.

Jaques’s earlier 1961 summary collapsed the array into eight modes to reflect the hypothesis that capacity is multi-modally distributed with genuine discontinuities between bands (Jaques & Stamp, 1990, ADA226910). In practical CPA administration the seven-band form is dominant because it aligns with the seven strata of work.

The five Styles

Separately from Mode, CPA reads a person’s decision-making Style — how they prefer to gather and interpret information. Five styles are identified (University of Pretoria dissertation; Wits dissertation citing Stamp 1981):

Style A — constantly in touch with the work, engrossed in details, one thing at a time; knowledge-in-action.
Style B — gets a view of the situation, defers commitment until data is analysed.
Style C — harnesses the ideas and strengths of reports; creates context.
Style D — uses ideas and concepts as filters; conceptual, analytical, detail-oriented.
Style E — relies little on immediate experience; looks for the unusual; creates knowledge in reflection.

Style is orthogonal to Mode and to processing type: two people at the same Mode can operate with different Styles.

Jaques and Cason’s Side — Human Capability and Types of Mental Processing

Human Capability (1994) reports a three-year study by Elliott Jaques and Kathryn Cason. Its central empirical claim is that when people are engrossed in problem solving, they use four — and only four — distinct patterns of mental processing (Global Organization Design Society summary; Requisite Organization, Perlego; Amazon description of Human Capability; Wikipedia summary).

The four Types of Mental Processing

Declarative — an or–or disjunctive logic. Presents separate reasons, each standing on its own without connection to others.
Cumulative (also called “accumulative”) — an and–and conjunctive logic. Brings multiple reasons together that collectively support the position.
Serial — an if–then conditional logic. Constructs a chain of linked reasoning where each step leads to the next.
Parallel — an if-and-only-if bi-conditional logic. Considers multiple serial chains simultaneously, comparing and interweaving them.

The four Orders of Information Complexity

The four types recur across four orders of information the mind can process (Global Organization Design Society; Amazon description of Human Capability; Reddit summary of Human Capability):

Order A — Concrete verbal. Directly observable things; the world of the child.
Order B — Symbolic verbal. Symbolic representations in everyday language; things chunked without pointing.
Order C — Abstract conceptual. Thoughts that refer to thoughts; systems of ideas.
Order D — Universals. Principles, paradigms, ideologies, foundational scientific theory.

The 4 × 4 recursive matrix

Because each type recurs at each order, the model generates 16 cells, notated as <Order><Type> — for example B3 = symbolic serial, C2 = conceptual cumulative (Global Organization Design Society).

Mapping to the seven SST strata

The Global Organization Design Society summary of Human Capability gives the canonical stratum-to-cell mapping. Strata I through IV all sit in the symbolic-verbal order (B), cycling through the four processing types; strata V through VII move up to the abstract-conceptual order (C):

Stratum I (up to 3 months) — B1, symbolic declarative.
Stratum II (3 months to 1 year) — B2, symbolic cumulative.
Stratum III (1 to 2 years) — B3, symbolic serial.
Stratum IV (2 to 5 years) — B4, symbolic parallel.
Stratum V (5 to 10 years) — C1, conceptual declarative.
Stratum VI (10 to 20 years) — C2, conceptual cumulative.
Stratum VII (20 to 50 years) — C3, conceptual serial.

The Cognadev summary of SST states the same structure in slightly different wording: the first four SST levels use the four processing types with symbolic verbal information; levels five to eight use the same four types with abstract conceptual information (Cognadev).

This mapping is Jaques and Cason’s contribution, not Stamp’s. It is what practitioners often, incorrectly, describe as “Stamp’s four modes.”

How the Two Sides Fit Together

Both frameworks are anchored in Stratified Systems Theory. They answer different questions, and the cleanest way to keep them straight is to name the question each one is built to answer.

Where can this person work today, and how far will they grow? — Stamp’s CPA. It produces a Current Level (I–VII), a Mode (I–VII), and a Style (A–E).

What is the underlying architecture of thought that lets someone operate at a given stratum? — Jaques and Cason’s Human Capability. It classifies a person’s problem-solving by Type of Mental Processing (declarative, cumulative, serial, parallel) at an Order of Information Complexity (A, B, C, D).

What is the shape of the organization the person is working in? — Jaques’s SST. It maps roles onto strata I through VII by time span of discretion.

The two are complementary. CPA is the assessment method used to place a person on a growth curve. The Human Capability matrix is the theory of the mind that explains why the growth curves have the shape they do. Both feed the same SST-based decisions about role design, succession, and development.

Application, Evidence, and Predictive Validity

CPA has been used in commercial, governmental, and military settings for over four decades.

Stamp’s longitudinal follow-up (1988) — reported in ARI Technical Report 819. In the refined-procedure follow-up group of 76 respondents over 4 to 13 years, the correlation between CPA-predicted potential and observed capability was r = 0.89. Restricted to the 59 respondents who remained in the same organization long enough for sustained progression to be observed, r = 0.92 (Jaques & Stamp, 1990, ADA226910; Anker Bioss summary of CPA evidence).
Lewis (1993, ARI Technical Report 983) — CPA data reduction and analysis; the technical documentation of the instrument and its scoring for U.S. Army use (DTIC ADA273225).
Oosthuizen, Coetzee & Kruger (2014) — test–retest reliability study of CPA on a sample of over 500 South African participants. Reported correlations of r = 0.67 between CLC readings across administrations and r = 0.59 between Mode readings, both large effect sizes at p ≤ 0.001. No significant race or gender differences in Mode (SAJIP).
Jacobs & Jaques (1990), “Military executive leadership” — chapter in Measures of Leadership (Clark & Clark, eds.), Leadership Library of America / Center for Creative Leadership. Reports predictive validities in the 0.7 to 0.9 range for conceptual capacity against advancement, supporting the SST-based approach as a whole (Global Organization Design Society, ARI research summary; University of Nebraska bibliographic reference).

Unlike intelligence or personality assessments, CPA measures how a person structures reasoning about work, not what they know or how they typically behave. It is designed to be free of bias from formal education level, gender, or ethnicity — a claim supported empirically by the Oosthuizen study and reiterated in Bioss and Anker Bioss materials (Anker Bioss; SAJIP).

Comparisons with Other Cognitive and Decision-Making Models

Piaget and Kegan — CPA and Human Capability are structural developmental theories in a Piagetian lineage, but they are calibrated to organizational levels of work rather than to childhood developmental milestones or adult meaning-making stages (Jaques, 1986, “The Development of Intellectual Capability,” Journal of Applied Behavioral Science).
Streufert’s cognitive complexity — an adjacent tradition that measures integrative complexity in decision behaviour, most often via simulation-based assessment. Streufert and colleagues (1978, 1986) argue that cognitively complex managers outperform less complex ones on complex tasks. It is a compatible but distinct line of research; the two traditions cross-cite each other (Vlerick review of cognitive style).
Trait models — MBTI, Hogan, Big Five — describe stable behavioural tendencies. They do not describe capability for complexity. CPA and Human Capability are orthogonal to these instruments and are typically used alongside them, not instead of them.

Critiques, Validations, and Adaptations

Assessor dependence. CPA is interpretive rather than mechanically scored. Predictive validity depends on assessor training, verbal skill of the interviewee, and rapport. This is the strongest recurring critique in the CPA literature (Cognadev on CPA validity factors).
Risk of deterministic labelling. Mode is a projected potential, not a ceiling. Stamp emphasised that the reading is longitudinal and dynamic, meant to inform development rather than to close it down (Bioss / Stamp; Anker Bioss).
Modified CPA (MCPA). A computer-based variant of the full CPA, jointly developed by EDAC and Bioss, drawing on Levels of Work theory from Stamp, Jaques, and Jacobs (SlidePlayer summary of MCPA).
Cross-cultural application. The Oosthuizen et al. (2014) South African study is the most recent large-sample published reliability check and supports the framework’s cross-cultural stability (SAJIP).
Contested strata count. Some formulations of the SST spine extend to eight levels (Cognadev; Bioss). The pragmatic seven-stratum form dominates commercial application; eight-level forms appear where an “extrapolating / transforming” tier is needed.

Conclusion

Gillian Stamp’s contribution should be described precisely. She built Career Path Appreciation, an interview-based method for reading a person’s current level of work decision-making capability and projecting their Mode — their future potential — against Jaques’s growth curves. In CPA there are seven modes (I–VII), aligned with the seven strata of Stratified Systems Theory, plus five decision-making Styles that describe how the person prefers to gather and arrange information.

The four familiar categories — declarative, cumulative, serial, parallel — are not Stamp’s four modes. They are Jaques and Cason’s four Types of Mental Processing from Human Capability (1994), which recur across four Orders of Information Complexity to generate a 4 × 4 matrix that maps onto the seven strata (B1, B2, B3, B4, C1, C2, C3).

Kept distinct, the two frameworks are more powerful than the conflated version. CPA provides the diagnostic; Human Capability provides the underlying theory of mind; SST provides the shared spine. Together they remain a durable foundation for succession, role design, and executive development four decades after Stamp first named the method.

References

Jacobs, T. O., & Jaques, E. (1990). Military executive leadership. In K. E. Clark & M. B. Clark (Eds.), Measures of leadership (pp. 281–295). West Orange, NJ: Leadership Library of America / Center for Creative Leadership. Full bibliographic record indexed at DTIC ADA312006.

Jaques, E. (1986). The development of intellectual capability: A discussion of Stratified Systems Theory. Journal of Applied Behavioral Science, 22(4), 361–383. https://doi.org/10.1177/002188638602200402

Jaques, E., & Cason, K. (1994). Human capability: A study of individual potential and its application. Arlington, VA: Cason Hall & Co. Bibliographic record: Google Books.

Jaques, E., & Stamp, G. (1990). Development of Stratified Systems Theory for possible implementation in the U.S. Army (ARI Research Note ADA226910). Alexandria, VA: U.S. Army Research Institute for the Behavioral and Social Sciences. Full text: https://apps.dtic.mil/sti/tr/pdf/ADA226910.pdf

Lewis, P. (1993). Career Path Appreciation (CPA) data reduction and analysis (ARI Technical Report 983). Alexandria, VA: U.S. Army Research Institute for the Behavioral and Social Sciences. Full text: https://apps.dtic.mil/sti/tr/pdf/ADA273225.pdf

Oosthuizen, R. M., Coetzee, M., & Kruger, E. (2014). Assessing the test–retest reliability of Career Path Appreciation as a measure of current and potential work decision-making capability. SA Journal of Industrial Psychology, 40(2), 1–11. https://doi.org/10.4102/sajip.v40i2.1199

Stamp, G. (1981). Levels and types of managerial capability. Journal of Management Studies, 18(3), 277–298. https://doi.org/10.1111/j.1467-6486.1981.tb00103.x

Stamp, G. (1988). Longitudinal research into methods of assessing managerial potential (ARI Technical Report 819). Alexandria, VA: U.S. Army Research Institute for the Behavioral and Social Sciences.

Stamp, G. (1989). The individual, the organisation and the path to mutual appreciation. Personnel Management, 21, 28–31. Reproduced by Bioss: https://www.bioss.com/gillian-stamp/the-individual-the-organisation-and-the-path-to-mutual-appreciation/

Stamp, G. (1993). The essence of levels of work. Johannesburg: Bioss Southern Africa.

Streufert, S., & Nogami, G. Y. (1989). Cognitive style and complexity: Implications for I/O psychology. In C. L. Cooper & I. Robertson (Eds.), International Review of Industrial and Organizational Psychology (pp. 93–143). Chichester: Wiley.