No theory forbids me to say "Ah!" or "Ugh!", but it forbids me the bogus theorization of my "Ah!" and "Ugh!" - the value judgments. - Theodor Julius Geiger (1960)

William Haddon jr.

While not a sociologist, Haddon's work in injury prevention is included here. He demonstrated an interdisciplinary and systems-oriented approach, involved public policy and advocacy, and he emphasized collaboration, data collection, and evaluation.


The Legacy of Dr. William Haddon Jr. in Injury Prevention

In our history, injuries were long neglected, but they gained recognition as a significant cause of death. Dr. William Haddon Jr. (1926-1985), a pioneer in the field of injury prevention, strived for a scientific approach to the prevention of injuries, just like the epidemiological approach he was familiar with for infectious diseases. Haddon strived to understand the causes of injuries and to develop effective strategies for their prevention and mitigation.

One key aspect of his work focused on recognizing that most injuries result from the exchange of mechanical energy. To combat this, strategies included not producing excessive energy, preventing its release, and separating individuals from potential energy sources. Haddon also studied the role of alcohol and drugs in injuries, particularly in motor vehicle accidents, and suggested to find system-oriented solutions rather than blaming individuals.

Haddon introduced the Haddon Matrix, a conceptual model that applies fundamental principles of public health to traffic safety. The Matrix breaks down the complexities of traffic safety interventions. It categorizes injuries into causal and contributing factors while considering their timing across three phases: pre-event, event, and post-event; interventions must be strategically planned well before a potential collision. Pre-crash phase interventions aim to reduce the number of collisions. Meanwhile, crash-phase interventions may not prevent the collision but can significantly reduce the severity and number of resulting injuries. Post-crash interventions focus on optimizing outcomes for those with injuries and preventing secondary events.

Comprising four (or three) columns, the matrix represents causal agents in traffic crashes: the driver, the vehicle, and the physical and socio-economic environment. Within these columns, twelve (or nine) cells spotlight specific areas where interventions can successful. Different agencies and organizations often converge on specific cells based on their policies and objectives; effective collaboration is needed to maximize their collective impact.

In the post-event phase, the focus is on maximizing salvage after injuries occur, encompassing emergency services, medical treatment, and rehabilitation. Haddon also emphasized the importance of data collection and evaluation to enhance the effectiveness of safety measures and inform the development of national safety standards.

Haddon's legacy shows the critical role of science and systems thinking in safeguarding lives. His work on passive protection measures, such as airbags, was important in enhancing safety without relying on individual actions.

These are Haddon's principles categorized into pre-event, event, and post-event phases for managing or mitigating risks:


  1. Prevent the existence of the agent: Aim to avoid or eliminate the presence of the harmful factor or agent.
  2. Prevent the release of the agent: Focus on stopping the exposure of the agent to the environment or potential hosts.
  3. Separate the agent from the host: Ensure a physical or environmental barrier between the harmful agent and the potential hosts.
  4. Provide protection for the host: Equip potential hosts with preventive measures to safeguard against the harmful agent.


  1. Minimize the amount of agent present: Reduce the quantity or level of exposure to the harmful agent.
  2. Control the pattern of release of the agent to minimize damage: Manage or regulate the way the agent is released to minimize its impact.
  3. Control the interaction between the agent and host to minimize damage: Manage or alter the interaction between the agent and potential hosts to reduce harm.
  4. Increase the resilience of the host: Strengthen the ability of potential hosts to withstand or cope with the harmful agent.


  1. Provide a rapid treatment response for the host: Offer swift medical or responsive measures after exposure to the harmful agent.
  2. Provide treatment and rehabilitation for the host: Offer ongoing medical care and support for recovery and rehabilitation after the event has occurred.