Method Participants

Fifty-five students from New York University (32 women and 25 men) participated in the experiment for partial course credit in an introductory psychology course. Students were randomly assigned to the three experimental conditions. The data of 3 participants were excluded from the analyses due to computer failure. Of the 52 participants included in the data analyses, 18 comprised the implementation intention condition, 19 the goal-only condition, and 15 the control condition.

Design

This experiment used a 3 (condition: implementation intention vs. goal-only vs.

control) x 4 (word type: implementation intention vs. goal-only vs. control) factorial design. The first factor varied between subjects, and the second factor varied within subjects. The dependant variable consisted of response latencies as measured by a lexical decision task.

Materials

One goal intention (in the form of “I will…”) plus six corresponding implementation intentions (in the form of “If…, then….”) were constructed. The study was conducted at the beginning of a fall-semester and most participants were students in their first year of university. Assuming that most students at that time are dealing with becoming integrated and forming new social relationships, the goal of “becoming socially integrated” was assigned as the goal intention. The implementation intentions were formulated to suit students and to serve the attainment of the goal intention (e.g.,

“If I am at the gym, then I will introduce myself to a fellow student.”). Each if-then plan contained two words for the LDT that corresponded to the situation (e.g., “gym”) and the goal-directed behavior (e.g., “introduce”). A word list was created that contained the

13 As participants in the goal-only condition and control condition had been exposed to the critical words via a word list but not to the neutral words, shorter response latencies for the critical words as compared to the neutral words were expected for them as well. However, this effect was expected to be stronger in the implementation intention condition.

situation- and behavior-words of the implementation intentions, as well as the same amount of additional words (12) unrelated to the situation- and behavior-words that never appeared in the experiment again (for a total of 24 words). Half of the additional words were misspelled words.

The LDT comprised three classes of items. First, it included the critical words, that is, the six situation-words and the six behavior-words of the implementation intentions. Each critical word was presented twice. Second, the LDT included the same number (12) of neutral but valid English words (hereafter called “neutral words”) that did not appear in the experiment and were matched in syllabic length to the critical words. Third, 36 orthographic non-words were included, such that the probability of word and non-word responses in the LDT was 50% each (for a total of 72 trials). The non-words were obtained from words (that were not used in the task) by changing one or two letters and were matched for syllabic length to the situation-, response- and neutral words.

Prior to running the Experiment, the situation-words, behavior-words, and neutral words were tested for semantic relatedness. To this end, 16 New York University undergraduate students were presented with initially selected critical and neutral words (presented in randomized order) and asked to generate as many associations to each presented word as possible. For each word, they were given 20 seconds to generate associations. Results revealed that 1 of the pre-chosen critical and 2 of the chosen neutral words had been generated as association to another pre-selected word. These words were eliminated as stimulus material and further suitable words were created. In a second round of word testing, 14 New York University undergraduate students participated. No association was found between any of the pre-selected words. Hence, these results ensured semantic un-relatedness of critical words among each other, of critical words to irrelevant words, and of irrelevant words among each other.

Procedure

Participants were greeted at a waiting area and escorted to the experimental room, where each was seated in an individual cubicle in front of a computer. The experiment was described as entailing several unrelated tasks involving word-related

judgments. Participants were told that they would be given experimental instructions either on the computer screen or in paper and pencil form.

Assignment of the goal. The first part of the experiment was presented in written form and was identical for the implementation intention and goal-only condition. First, participants were informed that a new semester was a good time to set personal goals and that they would be presented with a beneficial goal for students.

Then, they were asked to read the goal and to silently say it to themselves. Next, to instill high commitment to and deeper encoding of the prescribed goal, participants were asked to write down the goal.

Manipulation of implementation intentions. At this juncture, the instructions started to differ for participants in the implementation intention and the goal-only condition. Participants in the implementation intention condition were asked to read several consecutively presented plans that were deemed by the experimenter as effective ways to reach the goal they had been previously presented with. Next, to make sure that the participants adopted these plans, they were presented each implementation intention again and asked to fill in blanks that denoted the situation- and behavior-words (e.g., “If I am at the ____, then I will ____ myself.”).

In order to ensure equal exposure and encoding to the critical words to be used in the LDT across conditions, participants in the goal-only and control condition were presented with the word list. Next to each word, participants were asked to write the word down and in the case of the spelling errors, they were asked to correct the spelling when writing the word down.

Assessment of accessibility. The following task¹⁴ was a lexical decision task designed to measure the accessibility of the mental representation of the specified situation and the goal-directed behavior of the implementation intentions. The LDT was introduced as a task on lexical judgments and was identical for all conditions.

Instructions, sequence of a single trial (i.e., fixation cross, target-word), randomization of blocks, and measurement of response latencies were the same as in Experiment 1.

The 72 trials were divided into four blocks and were preceded by six practice trials.

14 As semantic un-relatedness among the critical words, the neutral words, and between the critical and neutral words was ensured by pilot-testing the words, there was no necessity to insert a distraction task (i.e., filler-task) between exposure to the critical words and assessment of their accessibility as in Experiment 1.

Post-experimental phase. As the effect of implementation intentions is contingent on the activation and strength of the underlying goal intention (see section 1.4.5 Implementation Intentions: A Cognitive Approach to Motivation herein), it was important to ensure participants’ importance of and commitment to the adopted goal.

Therefore, participants in the implementation intention and goal-only condition completed a questionnaire with the following four items in regard to the previously assigned goal: “How disappointed would you be in case you were not achieving this goal?”, “How important is the goal to you?”, “How feasible or easy do you think it would be for you to carry out this goal?”, and “How committed do you feel to this goal?”. Participants were asked to rate each question on a scale of 1 (low) to 7 (high).

At the end of the experiment, participants were thoroughly debriefed. The debriefing indicated that participants were unaware of the hypotheses under

investigation. No participant reported any suspicion about a connection between the different tasks.

2.2.3 Results and Discussion