hlid fish display was unknown. The researchers hypothesized that isotocin would suppress aggressive behaviors in cichlids to promote social cohesion as these fish exist in large social groups (schools). To address this hypothesis each of 10 fish were exposed to two treatments 1 week apart. One at a time a fish was randomly selected from the group of 10 and either injected with a saline solution ( that served as the control) or with isotocin. Af

Fish produce a hormone called isotocin, a hormone that is similar to oxytocin in mammals. Both hormones, oxytocin and isotocin, have been linked to social behaviors including the suppression of social anxiety, trust, and attachment. Prior to this study the relationship between isotocin in the bloodstream and the amount of aggression or submission individual cichlid fish display was unknown. The researchers hypothesized that isotocin would suppress aggressive behaviors in cichlids to promote social cohesion as these fish exist in large social groups (schools). To address this hypothesis each of 10 fish were exposed to two treatments 1 week apart. One at a time a fish was randomly selected from the group of 10 and either injected with a saline solution ( that served as the control) or with isotocin. After this injection the fish was returned to its group and the amount of aggressive and submissive behaviors the fish demonstrated was recorded for the next 10 minutes. One week later this process was repeated with each fish recieve f the treatment it did not experience the week prior. This each fish served as its own control. 1. In order to consistently score fish on their behaviors, what tool did the researchers likely produce prior to recording their behavioral data? 2. Based on the pattern of data collected ( not statistics) did the researchers find support for their hypothesis? Why or why not? 3. What approach (of Tinbergen’s 4) to understanding behavior did these researchers use? Explain your answer.