Person Recognition from Dynamic Events: The Kinematic Specification of Individual Identity in Walking Style

Three experiments used Johanssons [Perception and Psychophysics, 14, 201–211 (1973)] point-light technique to investigate, whether observers could correctly recognize others from their natural and deceptive walking styles based solely on the kinematic pattern produced when walking. Participants watched pairs of video-clips of unknown young male actors and judged whether the video-clips in each pair were from the same actor or not. The pairs of video-clips consisted of one clip of an actor walking naturally across a room and one clip of an actor attempting to walk deceptively (attempting to make themselves appear considerably older than they actually were). The results from Experiments 1a and 1b demonstrated that participants were fairly accurate at recognizing when the actors in the two video-clips were the same and when they were different. In addition, an invariant of walking style (weight shift) was shown to be an important kinematic feature for the identification of walkers. Experiment 2 demonstrated that those walkers whose weight shift differed between their natural and their deceptive walk were more effective in deceiving observers about their true identity than those whose weight shift was the same in the two walks. The results are discussed in relation to the kinematic specification of identity, and the production and perception of deceptive intent.Experiment 1 was completed as partial fulfillment of the requirements for Part 1 of an MSc (Hons) by the first author. This research was conducted with the financial assistance of University of Canterbury Research Committee Grant #U6279. Thanks are extended to Dean Owen, Rebekah Gunns & Kerry Marsh for their insightful comments.     

Why do “Women’s jobs” have low pay for their educational level?

Jobs held largely by women have low pay for the amount of education they require. Why is this? One hypothesis is that employers prefer to hire men, and all workers prefer better jobs, so that women can get in only when a job's rewards (relative to its skill requirements) are low enough that men no longer want the job. Thus, wages affect sex composition. Others see the causal arrow to run the other way. In this view, the sex composition of jobs affects the wage that employers offer; employers' biased perceptions lead them to see jobs as less important and less payworthy if they are filled largely by women. These explanations are not mutually exclusive; the causal arrow may run both ways (or neither way). In this paper we use CPS data from 1984 to 1991 and a cross-lag panel model to examine these effects. Jobs are defined with a detailed occupational category within a specific broad industry category. We find that jobs with a higher percentage of females at one point have slower wage growth (or steeper wage decline) for both men and women in the ensuing years. But we find no effect of earlier wage rate on later sex composition. For those interested in reducing gender inequality in earnings, these findings suggest the utility of “comparable worth” policies.     

Forensic sociology: Some cautions and recommendations

This paper uses a research experience involving change-of-venue research and jury work in a mass murder case as a vehicle for discussing a number of problem areas in forensic sociology. Included are discussions of time pressures, secrecy, special methodological problems, and the issue of researcher privilege and dealing with subpoenas. A number of recommendations are made to those planning to become involved in forensic sociology, including having access to legal counsel and special precautions to protect confidential sources. James T. Richardson, a professor of sociology at the University of Nevada-Reno, recently graduated from the Nevada School of Law and passed the Nevada Bar exam. He is a founder of Litigation Technologies, Inc., and is a co-owner of Market Systems Research, Inc. K. Gregory Swain and Jeffrey Codega are co-owners of Market Systems Research, Inc. and of Litigation Technologies, Inc. Kenneth Bazzell is a doctoral student in sociology at the University of Nevada-Reno.     

The Economic Impacts of a Terrorist Attack on the U.S. Commercial Aviation System

We use data on air passenger travel expenditures per passenger as well as statistical analysis of the air traffic lost for the two-year aftermath of the September 11, 2001, attacks to estimate direct demand losses for air transportation services. These are used along with a national input-output model to assess the full costs of these losses. Depending on assumptions made, the full losses to the U.S. economy were between $214.3 and $420.5 billion. These estimates are similar to those from other studies of such an event, and suggest that the high costs of effective countermeasures may be justified.     

High-dimensional regression in practice: an empirical study of finite-sample prediction,variable selection and ranking

Penalized likelihood approaches are widely used for high-dimensional regression. Although many methods have been proposed and the associated theory is now well developed, the relative efficacy of different approaches in finite-sample settings, as encountered in practice, remains incompletely understood. There is therefore a need for empirical investigations in this area that can offer practical insight and guidance to users. In this paper, we present a large-scale comparison of penalized regression methods. We distinguish between three related goals: prediction, variable selection and variable ranking. Our results span more than 2300 data-generating scenarios, including both synthetic and semisynthetic data (real covariates and simulated responses), allowing us to systematically consider the influence of various factors (sample size, dimensionality, sparsity, signal strength and multicollinearity). We consider several widely used approaches (Lasso, Adaptive Lasso, Elastic Net, Ridge Regression, SCAD, the Dantzig Selector and Stability Selection). We find considerable variation in performance between methods. Our results support a “no panacea” view, with no unambiguous winner across all scenarios or goals, even in this restricted setting where all data align well with the assumptions underlying the methods. The study allows us to make some recommendations as to which approaches may be most (or least) suitable given the goal and some data characteristics. Our empirical results complement existing theory and provide a resource to compare methods across a range of scenarios and metrics.     

Measuring the propensity to drink and drive

Laws such as .08 blood alcohol content, open container, and license revocation provide a policy framework for reducing drinking and driving. Drinking and driving behavior is difficult to assess; unlike property and violent crimes, where incidence statistics can approximate behavior, most drink-driving trips go undetected. The authors develop a novel measure of drink-driving propensity by estimating an item response model using national survey data. The authors illustrate their measures in the aggregate and as they relate to law enforcement efforts in the American states.     

Approaching ADHD as a chronic condition: implications for long-term adherence

Attention-deficit/hyperactivity disorder (ADHD) is one of the most common chronic conditions of childhood. Although evidence-based treatments for ADHD, including stimulant medication and behavior modification, have long been established, and guidelines for care of ADHD in primary care settings have been developed, adherence to long-term therapy is poor among youth with ADHD. This article proposes use of the Chronic Care Model for Child Health, the purpose of which is to develop informed, activated patients who will interact with a prepared, proactive health care team. Six "pillars" make up the model: decision support, delivery system design, clinical information systems, family and self-management support, community resources and policies, and health care organizations. Each of these is discussed, and an individual example is described. Adopting the Chronic Care Model for Child Health has the potential to improve the quality of care for ADHD.     

Youth masculinities: compelling male heterosexuality

This article seeks to extend understandings of heterosexual masculine identities through an examination of young men's constructions of what motivates young men to engage in heterosexual practices and relationships, and what not having sex might mean for them. Using the masculinity literature and work on heterosexuality to frame the discussion and to contextualize the findings, it explores the complex dynamics that frame the relationship between masculinity and heterosexuality. Specifically, how dominant or 'hegemonic' discourses of heterosexuality shape young men's identities, beliefs and behaviour. It considers these questions using empirical data from a qualitative study of young people living in close-knit working-class communities in the North East of England, with a specific focus on cultural and social attitudes towards sexuality and sexual practices. Peer group networks are a key site for the construction and (re)production of masculinity and, therefore, an important arena within which gendered social approval and acceptance is both sought and gained. In this article, I explore the reasons why young men engage in specific types of heterosexual practice in order to gain social approval. A central question is the extent to which heterosexuality is compelling for young men. That young men do feel compelled to behave in certain ways sexually, behaviours that they may be uncomfortable with and/or dislike, and the fact that they feel they are restricted in terms of how they can talk about their experiences within their peer group networks, demonstrates the power of dominant discourses of masculinity in everyday life. This is addressed through an examination of the restrictive effects of normative discourses about male heterosexuality, including their privatizing effects, which suggest that youth masculinities are often experienced in ways that are highly contradictory requiring young men to adopt a range of strategies to deal with this.     

Community and Individual Factors Associated with Cigarette Smoking Among Young Men Who Have Sex With Men

Young men who have sex with men (YMSM) have higher rates of cigarette smoking than their heterosexual counterparts, yet few studies have examined factors associated with cigarette smoking among YMSM. The present study sought to understand how different types of gay community connection (i.e., gay community identification and involvement, gay bar/club attendance) were associated with smoking among YMSM recruited through venue-based sampling in Los Angeles, California (N = 526). Structural equation modeling was used to isolate direct and indirect effects of gay community connection on smoking through cognitive and psychological mediators (i.e., psychological distress, health values, internalized homophobia). Findings indicate YMSM cigarette smoking prevention and intervention must be tailored to address the direct and indirect influences of the gay community.