본 연구는 대민지원활동 관련 육군의 소셜미디어 게시물에서 대민지원활동의 당위성을 언급하는 것과 해당 활동에 참여한 병사의 증언을 제시하는 것이 이용자의 선택의 자유 위협 지각과 심리적 저항의 순차적 매개를 거쳐 육군에 대한 신뢰에 어떠한 영향을 미치는지 검증했다. 아울러 이용자의 육군에 대한 기존 태도가 이러한 간접효과 과정을 어떻게 조절하는지 또한 탐색했다. 연구질문에 답하기 위해 2(대민지원활동 당위성: 언급 vs. 미언급) × 2(대민지원활동 참여 병사 증언: 제시 vs. 미제시) 피험자 간 요인 설계 실험을 온라인상에서 실시했다(N = 742). 연구 결과, 대민지원활동의 당위성을 명시적으로 언급한 게시물은 그렇지 않은 게시물과 비교해 수용자가 선택의 자유가 위협받는다는 지각을 덜 하게 했고, 이를 통해 심리적 저항을 감소시킴으로써 결국 육군에 대한 신뢰를 높이는 것으로 나타났다. 또한, 이러한 순차적 매개 과정을 거친 간접효과는 육군에 대한 기존 태도가 부정적일수록 더욱 커지는 것으로 확인되었다. 연구 결과의 이론적·실천적 함의를 논의했다.
This study aimed to examine how two intrinsic message features of the South Korean Army’s social media posts—the presentation of (a) a justification for the Army's involvement in civil support activities, and (b) a soldier’s testimony about such activities—indirectly affect users' trust in the Army by influencing their perceived threats to freedom of choice and, subsequently, their psychological reactance to the posts. The study also sought to explore how users’ prior attitudes toward the Army moderate these indirect effects. To this end, we conducted an online experiment using a 2 (justification mention: absent vs. present) x 2 (soldier testimonial: absent vs. present) between-subjects design. A total of 742 South Korean adults in their 20s and 30s participated in the experiment. The participants were randomly assigned to one of four experimental conditions, each featuring a different Instagram post promoting the Army's snow removal effort. The variations in these posts were based on (a) whether the post explained why such a civil support activity is a key mission of the Army, citing the names and numbers of the relevant law clauses, and (b) whether the post included a soldier’s personal testimonial about his experience in the activity. The results revealed that the participants who viewed an Instagram post providing justification information were less likely to perceive the post as threatening to their freedom of choice compared to those who were exposed to a post without such information. This reduction in perceived threats to freedom of choice, in turn, decreased their psychological reactance to the post, ultimately leading to an increase in trust in the Army. Furthermore, the positive indirect effect of justification mention on trust in the Army was contingent upon the participants’ prior attitudes toward the Army: the effect was statistically significant among those with unfavorable or moderate attitudes, but not among those with favorable attitudes. In contrast, the presence of a soldier’s testimonial in an Instagram post did not affect the extent to which the participants perceived the post as threatening to their freedom of choice; consequently, its indirect effect on their trust in the Army was not significant. Moreover, the effect of presenting a soldier’s testimonial did not hinge on the participants’ pre-existing attitudes toward the Army. The findings are discussed in light of their insights for both (a) theoretical implications for justification explicitness and psychological reactance, and (b) practical applications in military communication strategies on social media.