Can Crash Tests Lie?
As part of Levitt’s analysis, he and co-author Dubner hired a firm to conduct independent crash tests. Using the same three-year-old and six-year-old dummies as in federal crash tests, they tested the dummies in seatbelts alone, as well as in a car seat (for the three-year-old) and in a booster seat (for the six-year-old). Their results showed “nominally higher” head and chest acceleration for the three-year-old dummy in the seatbelts alone than in the car seat, and nearly identical results for the six-year-old dummy in both restraints. But these types of tests don’t simulate real-world scenarios as well as adult crash tests do. While child dummies’ hard plastic pelvises actually help hold the lap portion of the belt in place, real children’s pelvic bones, which aren’t fully developed, cannot. Further, children are more comfortable if their knees bend at the edge of the seat, and as a result, they often slump, causing the lap belt to ride too high and rest on their abdomens. In a crash
