The Near-Miss Effect in the Domestic Hen

Abstract

A near-miss in gambling is a loss situation which presents a similar stimulus to a win (e.g., two out of three reels that display an identical symbol on a pokie machine). The near-miss is thought by some to reinforce gambling behaviour, even though the outcome is still a loss. Some studies suggest that near-misses might function as conditioned reinforcers. To investigate a relationship between a near-miss event and conditioned reinforcement, six hens were exposed to concurrent VI schedules with two response keys. A response to one key provided a magazine light and food reinforcers in random order or food reinforcers only (the A1 key) while the other key provided food reinforcers only (the A2 key). From Conditions 2 to 4, the total reinforcer proportion was 2:1 for the A1 key: A2 key under VI 30-s VI 60-s schedule. From Conditions 5 to 10, the total reinforcer proportion (the proportion of food and conditioned reinforcers) was 4:1 under VI 25-s VI 100-s schedule. Response proportions and average responses were analysed in this study. The findings suggested that the subjects’ response proportion and average responses on the A1 key were only significantly higher than on the A2 key when the A1 key provided more food reinforcers than the A2 key. There were two conditions which might indicate that the magazine light-stimulus might function as a conditioned reinforcer, however. In Condition 7, the hens’ responses significantly increased from the previous identical condition (Condition 5). In Condition 10, Hens 71 and 72 increased the response proportion from the previous identical condition (Condition 8) while Hen 76 decreased the proportion. Further study is required to determine if the near-misses can reinforce a hen’s behaviour.