Book of the Month: Stress and Human Performance (Driskell & Salas (eds))

About the editors

Eduardo Salas is currently Professor of Psychology and Program Director for the Human Systems Integration Research Department at the Institute for Simulation & Training at the University of Central Florida. When this book was published in 1996, Salas was a senior research psychologist and Head of the Training Systems Division at the Naval Air Warfare Center, Orlando, Florida.

James E. Driskell is President and Senior Scientist, Florida Maxima Corporation and Adjunct Professor, Rollins College, Winter Park, Florida. The Florida Maxima Corporation is, according to its website "a small business that conducts basic and applied research in the social and behavioral sciences in government, academia, and industry."

Salas and Driskell continue to collaborate on topics such as deception, team performance and stress.

About the contributors

There are 17 contributors to this book, including the 2 editors. The foreword states: "this book brings together a set of authors who are not only prominent researchers within this field, but are also actively involved in the application of this research to real-world settings." Unfortunately only 2 of the authors are not from the US and 8 of them work in Florida. It is possible that the rest of the world had nothing to add to this book but more likely that the strong tendency to collaborate with people you know meant that this book is rather US-focused.

Who should read this book?

This book was written for:

"...researchers in applied psychology, human factors, training and industrial/organizational psychology. (As well as) practitioners in industry, the military, aviation, medicine, law enforcement, and other areas in which effective performance under stress is required"(p. viii)

The editors are clear that this book deals with acute stress, and not with chronic stressors, stress-related disorders or "coping". By acute stress the editors mean "emergency conditions" where the stress is novel, intense and time-limited.

Parts of the book are relevant to the simulation-based medical educator (see below).

In summary

The book is split into 3 main sections:

1. Introduction. A chapter looking at definitions of stress and its effect on performance.
2. Stress Effects. 4 chapters which look at how stress affects performance.
1. The effect of acute stressors on decision making
• Looks at decision-making strategies (non-analytical and analytical; similar to Kahneman's System 1 and 2; recognition-primed, naturalistic etc.)
2. Stress and military performance
• Looks at stressors of military personnel and methods for improving performance under stress (including CRM). Importance of team training.
3. Stress and aircrew performance: A team-level perspective
• Importance of teamworking and teamwork training, for dividing up tasks, for monitoring one another's behaviour and for providing support
4. Moderating the performance effects of stressors
3. Interventions. 3 chapters which look at how to minimise the effects of stress.
1. Selection of personnel for hazardous performance
2. Training for stress exposure
• Fidelity requirements; sequencing and training content
3. Training effective performance under stress: queries, dilemmas, and possible solutions

I haven't got time to read 295 pages!

Read the following bits (depending on your area of interest):

Chapter 1 for a good introduction and overview of stress and its impact on performance. 

Chapter 2 p.69-83 for a very good description of USS Vincennes shooting-down of the Iranian airliner.
Chapter 3 p.105-116 to understand why team training is important (not just because it looks good).

Chapter 4 p.143-149 for an overview of how an organisation can help or hinder team performance

Chapter 6 p.203-206 and 213-217 for an overview of personality types and stress

Chapter 7 p.247-253 for Stress exposure training (SET) guidelines

Chapter 8 p.272 for concluding remarks on training effective performance

Chapter 9 if you're interested in human-system interface issues

What's good about this book?

The book is generally well-written and, on the whole, the arguments made are easy to follow. We are told how stress may be defined by orientation to the environment (i.e. the environment is a stressful one), by orientation to the individual or by orientation to the relationship between the environment and the individual. The editors prefer the latter and provide a nice working definition of stress (quoting Lazarus and Folkman (1984)):

"Psychological stress is a particular relationship between the person and the environment that is appraised by the person as taxing or exceeding his or her resources and endangering his or her well-being" (p.6)

The editors therefore distinguish between a threat, where the capacity to respond is exceeded, and a challenge, where the person has sufficient capacity to respond and the expected gain exceeds potential harm. By the same token, "stress" is in the eye of the beholder and what is stressful to one person will be a minor challenge to someone else.

There is a good explanation of two different theories of task load. The first is the bucket (or capacity) theory, where a limited pool of attentional resources is available and when the bucket is "full" there is a reduction in performance. The second is the structural theory which envisages a parallel processing system which must go through an attentional serial bottleneck and it is this bottleneck which slows down performance.

There is a good discussion of the impact of the organisation on the team, including how the organisation forms teams, how it supports them and how it helps teams to interface with one another. The recommendations in terms of support include:

1. A reward system that provides positive reinforcement for excellent team work
2. An education system that provides the relevant training and resources required by team members
3. An information system that provides (in a timely fashion) the data and resources necessary to assess, evaluate and formulate effective crew coordination strategies

What's bad about this book? 

The book specifically does not look at chronic stressors, such as life stress, fatigue or sleep loss. Nor does it examine the effects of boredom on performance. Unfortunately we don't live or work in that utopian world where those influences are irrelevant. It may in fact be the case that the chronic stressors play a significant, even pivotal, part in turning a challenge into a threat, overwhelming our coping mechanisms. A book which refers to both chronic and acute stressors and their (synergistic?) role in failures would be very welcome.

Klein's chapter (Chapter 2: The Effect of Acute Stressors on Decision Making) is a confusing addition. In a book on stress and performance, Klein states:

"(Stressors) can degrade the quality of judgments, prevent the use of rational decision strategies, and severely compromise performance; at least that is a popular appraisal of stressors. The thesis of this chapter is that each of these assertions is either incorrect or misleading"(p.49)

Klein does try and mitigate this statement by then arguing that time stress, for example, leads to poor performance not because of the increase in stress but the decrease in time. He also argues that naturalistic decision-making is not "rational" anyway, is resistant to stress and that stress can improve performance. By p. 55 he is back-tracking slightly: "At the beginning of this chapter we claimed that stressors do not necessarily degrade decision making. (my italics)" The chapter reads poorly and Klein constructs straw men using semantic arguments about what "stress" really means.

In addition, although the book is presented as starting off with a section on stress and its effects followed by a section on dealing with stress, some of the earlier chapters (e.g. chapter 3) have "dealing with stress" sub-sections within them.

Final thoughts

There are repeated instances where, although simulation is not referred to, the benefits of using simulation to deal with or train for stress are made evident. For example, on page 12 "The development of positive performance expectations is a crucial factor in preparing personnel to operate under high-demand conditions."On page 15 "…performers were less distracted (by noise) when the task was well-practiced". On page 83 "To help decision makers avoid potential disruptions due to stressors, it may be useful to train them to better manage time pressure, distracting levels of noise, and high workload."

This book also provides the SBMEducator with some ammunition for courses with advanced-level participants. Stress can be induced using noise, group pressure, task load, threat or time pressure. In addition, stress can be induced by task similarity, so if you want to distract the participant use a visual distraction for when they need to focus on a visual task and auditory distractions when the task relies on auditory cues.

This book has emphasised the need to look at how we, as simulation providers, can both ensure that the environment is stressful enough (to ensure learning) but not so stressful that the participants are overwhelmed. In addition, we could do more to help participants recognise their stress reactions for what they are and explore with them how they can continue to perform optimally under stressful conditions. Lastly, SBME can increase the skills and skill levels of participants and, at the same time, make participants more aware of where their personal capabilities lie.

Rent this book out and read the sections which are relevant to your work, it will increase your understanding of stress, its effects and preventive/mitigating actions.