The importance of the secure base effect for domestic dogs - evidence from a manipulative problem-solving task

Abstract

Background: It has been suggested that dogs display a secure base effect similar to that found in human children (i.e., using the owner as a secure base for interacting with the environment). In children, this effect influences their daily lives and importantly also their performance in cognitive testing. Here, we investigate the importance of the secure base effect for dogs in a problem-solving task.

Methodology/principal findings: Using a manipulative task, we tested dogs in three conditions, in which we varied the owner's presence and behavior (Experiment 1: "Absent owner", "Silent owner", "Encouraging owner") and in one additional condition, in which the owner was replaced by an unfamiliar human (Experiment 2: "Replaced owner"). We found that the dogs' duration of manipulating the apparatus was longer when their owner was present than absent, irrespective of the owner's behavior. The presence of an unfamiliar human however did not increase their manipulation. Furthermore, the reduced manipulation during the absence of the owner was not correlated with the dog's degree of separation distress scored in a preceding attachment experiment.

Conclusions/significance: Our study is the first to provide evidence for an owner-specific secure base effect in dogs that extends from attachment tests to other areas of dogs' lives and also manifests itself in cognitive testing - thereby confirming the remarkable similarity between the secure base effect in dogs and in human children. These results also have important implications for behavioral testing in dogs, because the presence or absence of the owner during a test situation might substantially influence dogs' motivation and therefore the outcome of the test.

Figure 1. Apparatuses used in the experiment.

a) Folded cotton towel used in the pre-test, b) Nina Ottosson^© Dog Pyramid (aDP), c) Hunter^© Snack Cactus (aSC), d) Hunter^© Snack Bottle (aSB), e) the smaller version of the Hunter^© Rolling Snack (aRS).

Figure 2. Schematic representation of the experimental set-up.

The experimental room was equipped with two doors, one connecting it to the hallway (Door 1) and one connecting it to an adjacent room with monitoring and recording equipment (Door 2). At the beginning of each trial, the dog was released by the experimenter from the release point, which was 2.5 m away from the apparatus. During each trial the experimenter stood on the right side of door 1 – timing the trial with a clock on the opposite wall. The owner either sat on the designated chair on the left side of door 1 or was in the adjacent room – depending on the pre-test trial or the condition of the test trial. The dashed lines indicate the floor markings around the owner's chair and the experimenter's position, which were used for later video coding.

Figure 3. Duration of manipulating the apparatus –

Experiment 1 . Mean duration of manipulating the apparatus in the conditions “Absent owner” (cAO), “Silent owner” (cSO), and “Encouraging owner” (cEO). Shown are mean ± s.e.m. *** represents P≤0.001.

Figure 4. Duration spent in the proximity of the experimenter –

Experiment 1 . Mean duration spent in the proximity of the experimenter in the conditions “Absent owner” (cAO), “Silent owner” (cSO), and “Encouraging owner” (cEO). White bars represent the 1^st trials, striped bars represent the 2^nd trials, grey bars represent the 3^rd trials. Shown are mean ± s.e.m. * represents P≤0.05.

Figure 5. Duration of manipulating the apparatus –

Experiment 2 . Mean duration of manipulating the apparatus in the conditions “Absent owner” (cAO), “Replaced owner” (cRO), “Silent owner” (cSO), and “Encouraging owner” (cEO). Shown are mean ± s.e.m. *** represents P≤0.001, ** represents P≤0.01.

Figure 6. Duration spent in the proximity of the owner and the unfamiliar human –

Experiment 2 . Graph depicts box plots of duration spent in the proximity of the unfamiliar human (cRO) and of the owner (cSO), respectively. For each box plot, median values are indicated by the line within the box. The box represents 50% of the values (25th and 75th percentiles), with the upper bar representing the 90th percentile and the lower bar representing the 10th percentile. Circles indicate outliers. ** represents P≤0.01.