sacrificed in favor of heightened awareness of the threat
directly in front of us. In a critical sense, the police officers
whom Klinger describes performed better because their senses
narrowed: that narrowing allowed them to focus on the threat
in front of them.
But what happens when this stress response is taken to an
extreme? Dave Grossman, a former army lieutenant colonel and
the author of On Killing, argues that the optimal state of
“arousal” — the range in which stress improves performance —
is when our heart rate is between 115 and 145 beats per
minute. Grossman says that when he measured the heart rate of
champion marksman Ron Avery, Avery’s pulse was at the top of
that range when he was performing in the field. The basketball
superstar Larry Bird used to say that at critical moments in the
game, the court would go quiet and the players would seem to
be moving in slow motion. He clearly played basketball in that
same optimal range of arousal in which Ron Avery performed.
But very few basketball players see the court as clearly as Larry
Bird did, and that’s because very few people play in that
optimal range. Most of us, under pressure, get too aroused, and
past a certain point, our bodies begin shutting down so many
sources of information that we start to become useless.