madman
Super Moderator
Hormone administration
Testosterone or placebo conditions were randomly assigned, and administration was conducted using a double-blind procedure. Men assigned to the testosterone condition received two syringes of Natesto™, each containing 5.5 mg of gel, while men in the placebo condition received two syringes of an equivalent amount of non-active gel with similar physical properties (i.e., viscosity, color). Under the supervision of a research assistant, participants were instructed to apply the gel from one syringe to the lateral side of the left nostril, and the gel from the other syringe to the lateral side of the right nostril, and then to compress the nostrils toward the nasal septum to evenly spread the gel on nostril walls. Following administration, participants were instructed to immediately and thoroughly wash their hands in order to prevent unintentional contamination of any testing areas. The present protocol was the first to employ the hormone methodology identified above in a sample of healthy, eugonadal men (see [46] for pharmacokinetics in hypogonadal men), and thus a pharmacokinetic pilot was first conducted in order to establish the time course in this population (see [32] for full methods). Briefly, using a separate sample of men, and a doubleblind, cross-over design (with 2-week washout), male participants (n = 13) had a baseline blood draw, then received 11 mg of Natesto or equivalent placebo, followed by a blood draw at 15, 30, 60, and 180 min post-administration. As expected, groups did not differ in serum testosterone concentrations at baseline, but significantly differed at all post-administration time points (all p's < 0.005; Cohen’s dz range = 0.83–1.38). Notably, the greatest difference in testosterone concentrations occurred at 60 min post administration—the time at which behavioral testing for the current study was conducted.
Our hypotheses were partially informed by the idea that testosterone can promote impulsive behavior, such as reactive aggression. While testosterone did seem to increase cooperation in the time-pressure condition for high risk men, it did not reach statistical significance. It is possible that cooperation as an impulsive/intuitive behavior is different than impulsive aggression following provocation. Given that testosterone is highly implicated in social dominance behaviors, and reflexive dominance behaviors are often triggered by direct social threats (reviewed in [67]), testosterone may simply not function in the same manner in the context of having to make a cooperative decision under timepressure as it does when an individual is directly provoked. A further distinction may be made between the one-shot PGG and
paradigms typically used to examine aggressive responses. In the one-shot PGG, participants interact with “other participants” on one occasion only, and thus there is no risk for retaliation and/or social sanctions. In aggression paradigms like the PSAP, however, interactions with other participants are longer and dynamic, with many opportunities for retaliation throughout the task. Dreher et al. [25] found that testosterone increased both prosocial and antisocial status-enhancing behaviors in human men, but notably, their experiment involved repeated ultimatum games, where testosterone increased prosocial behavior only following the receipt of large offers from their game partner. Therefore, in a oneshot PGG, testosterone may not predict impulsive prosociality, but may in a context of available information about game partners. It may be useful for future studies to employ exogenous testosterone administration in the context of a repeated PGG with time pressure and forced-delay manipulations to allow a test of this hypothesis.
Testosterone or placebo conditions were randomly assigned, and administration was conducted using a double-blind procedure. Men assigned to the testosterone condition received two syringes of Natesto™, each containing 5.5 mg of gel, while men in the placebo condition received two syringes of an equivalent amount of non-active gel with similar physical properties (i.e., viscosity, color). Under the supervision of a research assistant, participants were instructed to apply the gel from one syringe to the lateral side of the left nostril, and the gel from the other syringe to the lateral side of the right nostril, and then to compress the nostrils toward the nasal septum to evenly spread the gel on nostril walls. Following administration, participants were instructed to immediately and thoroughly wash their hands in order to prevent unintentional contamination of any testing areas. The present protocol was the first to employ the hormone methodology identified above in a sample of healthy, eugonadal men (see [46] for pharmacokinetics in hypogonadal men), and thus a pharmacokinetic pilot was first conducted in order to establish the time course in this population (see [32] for full methods). Briefly, using a separate sample of men, and a doubleblind, cross-over design (with 2-week washout), male participants (n = 13) had a baseline blood draw, then received 11 mg of Natesto or equivalent placebo, followed by a blood draw at 15, 30, 60, and 180 min post-administration. As expected, groups did not differ in serum testosterone concentrations at baseline, but significantly differed at all post-administration time points (all p's < 0.005; Cohen’s dz range = 0.83–1.38). Notably, the greatest difference in testosterone concentrations occurred at 60 min post administration—the time at which behavioral testing for the current study was conducted.
Our hypotheses were partially informed by the idea that testosterone can promote impulsive behavior, such as reactive aggression. While testosterone did seem to increase cooperation in the time-pressure condition for high risk men, it did not reach statistical significance. It is possible that cooperation as an impulsive/intuitive behavior is different than impulsive aggression following provocation. Given that testosterone is highly implicated in social dominance behaviors, and reflexive dominance behaviors are often triggered by direct social threats (reviewed in [67]), testosterone may simply not function in the same manner in the context of having to make a cooperative decision under timepressure as it does when an individual is directly provoked. A further distinction may be made between the one-shot PGG and
paradigms typically used to examine aggressive responses. In the one-shot PGG, participants interact with “other participants” on one occasion only, and thus there is no risk for retaliation and/or social sanctions. In aggression paradigms like the PSAP, however, interactions with other participants are longer and dynamic, with many opportunities for retaliation throughout the task. Dreher et al. [25] found that testosterone increased both prosocial and antisocial status-enhancing behaviors in human men, but notably, their experiment involved repeated ultimatum games, where testosterone increased prosocial behavior only following the receipt of large offers from their game partner. Therefore, in a oneshot PGG, testosterone may not predict impulsive prosociality, but may in a context of available information about game partners. It may be useful for future studies to employ exogenous testosterone administration in the context of a repeated PGG with time pressure and forced-delay manipulations to allow a test of this hypothesis.
Last edited:
