by Graeme Newman (Author), Sheldon Glueck (Author), Eleanor Glueck

What makes a boy a persistent delinquent? A reader's guide to one of criminology's great matched-comparison studies.

In 1939, Sheldon and Eleanor Glueck of Harvard stopped asking what happens to offenders after they are caught and asked a harder question: why do some boys from the same poor neighborhoods become persistent delinquents while others do not?

Their answer, Unraveling Juvenile Delinquency (1950), compared 500 delinquent boys with 500 non-delinquents, matched pair by pair on age, intelligence, ethnic origin and neighborhood. They examined family life, schooling, health, body build, intelligence, personality and temperament. Then they built "prediction tables" meant to spot at-risk children when they start school.

The book is long, technical and dated in its language. This Reader's Guide makes it accessible without replacing it. It explains how the study was designed, what it found, and how far its evidence can be trusted, and it connects the Gluecks to the research that followed.

INSIDE THIS GUIDE

• A reading plan and a chapter-by-chapter map of the original

• How the two groups were built, and what the design can and cannot show

• The findings on family, school, the street, health, physique, intelligence and temperament, explained in plain language

• The prediction tables, with a worked example that shows why "79 chances in a hundred" can mean something quite different in real life

• Five common misreadings of the book

• What has changed since 1950, including later reanalyses of the Gluecks' data, and what has not

• A primer on statistics, a glossary, an annotated reading list, an FAQ, 26 discussion questions and classroom activities

WHO IT'S FOR: Students of criminology, sociology, psychology, social work and law; teachers and reading groups; and general readers who want to understand a landmark study and the debates it started, from risk assessment to the role of the family.

Part of the Read-Me.Org Reader's Guide series, bringing back landmark out-of-print works in criminology and social science..

NOTE: This is an independent guide, not an abridgment or edition of the Gluecks' book. It does not reproduce the original's text or tables and is not endorsed by the authors' heirs or the original publisher. It is meant to be read alongside the original. Written by Graeme R. Newman with the assistance of Claude, an AI model made by Anthropic. The AI-generated content is disclosed in accordance with Read-Me.Org policy.

Read-Me.Org Inc. New York-Philadelphia-Australia. 2026. p.67.

by Graeme Newman (Author), Sheldon Glueck (Author), Eleanor Glueck

Does the shape of a body shape a life?

In 1956, Harvard criminologists Sheldon and Eleanor Glueck published one of the most provocative findings in the history of criminology: among the 500 persistent juvenile delinquents at the heart of their landmark study, six in ten were built like athletes — solid, muscular, "mesomorphic" — compared to fewer than one in three of the matched non-delinquent boys from the very same streets. Boys of slight, fragile build were strikingly rare among the delinquents. Matched for age, intelligence, ethnicity, and neighborhood, the two groups differed sharply in one thing neither had chosen: the body they were born with.

Physique and Delinquency is the Gluecks' full investigation of what that difference meant — and what it didn't. Carefully, methodically, and explicitly rejecting the old "born criminal" theories of the nineteenth century, the Gluecks set out to show that physical constitution is not destiny. Instead, they found something more nuanced and more interesting: the very same trait, and the very same troubled home, can push a sturdy, energetic boy toward trouble while leaving a more sensitive, delicately built boy untouched — and can devastate that same sensitive boy when the pressures at home turn severe.

This Read-Me.Org Mini-Classic distills the Gluecks' densely tabulated 1956 original into a compact, readable narrative — every chapter, every major finding, and the six theoretical hypotheses that close the book — while leaving the statistical tables and technical appendixes to specialists and to the full edition. It's an ideal introduction for students of criminology, psychology, and the history of science, and for anyone curious about a study that remains as influential as it is uncomfortable, nearly seventy years after it first raised the question.

Includes a new introductory essay situating the book in its historical context, and a set of review and discussion questions suited to classroom or book-club use.

Part of the Read-Me.Org Mini-Classics series — short, careful introductions to landmark and forgotten works of criminology, sociology, and social history.

This edition was prepared with AI assistance used to condense and adapt the source text under human editorial review; abridgment choices and framing are the editor's own. Published under Creative Commons licensing.

Read-Me.Org Inc. New York-Philadelphia-Australia. 2026. p.80.

By David B. Wilson, Mark W. Lipsey

Research summary

The primary outcome desired for juvenile delinquency programs is the cessation of delinquent and related problematic behaviors. However, this outcome is almost always pursued by attempting to change intermediate outcomes, such as family functioning, improved mental health, or peer relations. We can conceptualize intermediate outcomes that are related to reduced delinquency as change levers for effective intervention. A large meta-analysis identified several school-related change levers, including school engagement (i.e., improved attendance and reduced truancy), nondelinquent problem behaviors, and attitudes about school and teachers. In addition, family functioning and reducing substance use were also effective change levers. In contrast, effects on youth getting/keeping a job, peer relationships, and academic achievement were not associated with reduced delinquency.

Policy implications

Only a small percentage of rehabilitative programs provided to youth involved in the juvenile justice system have been established as evidence based. Moreover, there are constraints on what local policy makers and practitioners can do regarding the selection, adoption, and implementation of programs from the available lists of evidence-based programs. Adopting programs that focus on effective change levers and avoiding those that concentrate on ineffective ones has the potential to increase the likelihood that a local agency is engaged in effective programming. Based on our data, programs known to improve family functioning, attachment to and involvement in schooling, and reducing substance use are justified by the change lever evidence, even if these programs’ effectiveness in reducing delinquency has not been directly proven. In contrast, programs focusing on vocational skills, academic achievement, and peer relations are less likely to be beneficial. Furthermore, a change lever perspective can help frontline staff select appropriate programs for different juvenile offenders and focus their quality control efforts on those aspects of a program that are likely to be essential to maintaining effectiveness.

Criminology & Public Policy Volume23, Issue2. May 2024.

David C. Pyrooz

This final summary overview describes a research project aimed at evaluating a gang intervention program, led by the Gang Reduction Initiative of Denver (GRID), which has historically coordinated around two dozen strategies with partners emphasizing prevention, intervention, and suppression. The focus of GRID’s efforts is their use of juvenile and adult multidisciplinary teams (MDT) to facilitate coordination and individual case management of gang-involved youth who have been referred for services. A process and impact evaluation was undertaken between 2019 and 2022, and the project was pre-registered on the Open Science Framework before data collection. The evaluation was guided by two core questions: if the MDT-based approach achieves its stated purpose of providing comprehensive, coordinated services to gang members with fidelity; and if the MDT-based approach achieves its stated goals of producing disengagement from gangs and desistence from crime. The first question was the focus of the process evaluation, and the second question was the focus of the impact evaluation. This report provides details about the evaluation’s methodology and informs that evaluation findings were mixed. Findings showed: there is clear evidence, from the process evaluation, that GRID delivered a range of high-quality services with efficacy; GRID clients were nearly 70 percent less likely to engage in violence than individuals in the control group; and GRID clients were more than three times more likely to claim a current gang status than control group participants.

Boulder, CO: Institute of Behavioral Science , University of Colorado, 2023. 28p.

By Jennifer Roark

This study, informed by a life course perspective, used a mixed methodological approach to identify the differences in events, motivations, and experiences related to gang affiliation and the differences across (a) system-documented, gang-involved individuals, (b) system-documented gang-involved individuals who have gang-involved family members, and (c) other high-risk youth who are suspected of involvement. The results of this study produced a nuanced understanding of these youth’s lives, especially as it relates to their fathers. As expected, when fathers were identified as having involvement in gangs themselves, youths were significantly more likely to also become members. The overall goal of this research was to identify distinct pathways to gang activity that could inform practitioners and policymakers about useful intervention strategies. This research fills a literature gap about the relationships between and amongst fathers and sons, and how those relationships transmit both criminogenic and protective factors that would encourage or discourage gang affiliation and gang activity. Father gang involvement continued to be a strong predictor of youth gang involvement even when controlling for other social relationships (e.g., peers, siblings, cousins), but not as much as same generation and peer influence. Importantly, fathers were not the sole social influence on a youth’s decision to join a gang. Peer and same generation family (siblings and cousins) gang involvement were as strong or stronger predictors of a youth’s involvement in crime and gangs as were the variables associated with fathers. The findings unexpectedly revealed that an increase in the most logged life events during a three-month timeframe reduced risk of escalation as a youth.

Portland, OR:  Research and Planning, Department of Community Justice Multnomah County Oregon. 2023, 113pg

By Ieke de Vriesl, Michael Baglivio, and Joan A. Reid

Despite extant literature on individual-level risk factors for sex trafficking among children and adolescents, little is known about the impact of social and ecological contexts on risk of human trafficking victimization. The purpose of this study was to examine the correlates signaling risk of human trafficking victimization at the individual, family, social, and community levels utilizing a sample of 40,531 justice-involved male and female youth, a small fraction of whom were suspected or verified victims of human trafficking between 2011 and 2015 (N = 801, including 699 female and 102 male youth). Using this sample, we examined differences across individual, family, social, and community characteristics of youth involved in the juvenile justice system who have a history of trafficking victimization and youth without such histories. Series of logistic regression analyses were conducted using varying control groups, created through exact matching and randomized matching groups to address sample imbalances. These analyses indicate that, at the individual level, youth who had experienced childhood adversities were more likely to report human trafficking victimization. Sex differences were found regarding risk factors pertaining to the family and broader socio-ecological contexts. Female youth who had witnessed family violence had an antisocial partner or antisocial friends, or resided in a community with a greater proportion of the population being foreign-born or speaking English less than very well were at heightened risk for human trafficking victimization. Little evidence was found for community-level risk factors of victimization in this specific sample of justice-involved youth. These findings encourage more research to unpack the multilevel correlates of victimizations at the individual, family, social, and community levels, recognizing potential differences between female and male youth regarding the factors that put them at heightened risk for juvenile sex trafficking victimizations. Practice and policy should direct awareness and prevention measures to social and ecological contexts.

By Michael John Cahill, Sarah Napier, Dana Thomsen, Micheala McCaig and Heather Wolbers 

This study analyses Australian Bureau of Statistics data to examine trends in the rate of juveniles being proceeded against by police for sexual offences in Australia, from 2008–09 to 2020–21. Over the 13-year period, the rate of recorded sexual offences committed by juveniles per 100,000 population was consistently higher than the rate for adults. While recorded assaultive sexual offences committed by juveniles decreased during this period, recorded non-assaultive sexual offences increased notably, and were still increasing at the end of the study period.

The study highlights the need for increased focus on early intervention (from the age of 13 onwards) and prevention efforts targeting non-assaultive sexual offending by both sexes and assaultive sexual offences by male juveniles in Australia.

Canberra: Australian Institute of Criminology. 2024, 16pg