Real Cliff / Water Cliff cross-sectional study [Dataset]

The present study examined crawling and walking infants’ avoidance and exploratory behaviour on the Real Cliff / Water Cliff (RC/WC) apparatus. The RC/WC apparatus consists of a 200 x 120 x 75cm platform with a real cliff at one end and a water cliff at the opposite end. Climbing equipment was used to ensure infant’s safety. The main aim of this study was to investigate the impact of specific locomotor experiences on infants’ avoidance of falling on the real and the water cliffs and to compare infants’ avoidance and exploratory behaviours on the real and the water cliffs. Infants were tested once on the real cliff and once on the water cliff, with trial order counterbalanced. The experimenter placed the infants close to the opposite edge of the platform. After the trial was initiated, the experimenter would only interfere with the infants’ movements if they did not move from the starting position during the first minute, in which case the experimenter would place them near the platform edge. The trials ended: (a) after 180s, if the infant had moved from the starting position but had not reached the platform edge; (b) 150s after the infant reached the platform edge; (c) when the infant fell off or descended from the platform edge; (d) when the infant started showing signs of distress or fussiness. If the infant showed signs of distress or fussiness during the first 60s of the trial and was not able to be calmed down, the test was ended and the infant was excluded from subsequent analyses. If the infant showed signs of distress or fussiness after 60s of reaching the edge, the test was ended, and the infant was coded as an avoider. Infants were free to move around and explore the platform while their mothers were calling them.
Infants were code for: Avoidance behaviour: Infants who fell from the platform were coded as “fell”. Infants who stayed on the platform until the end of the trial were coded as “avoided” and infants who adapted their behaviour by turning around, laying their bellies on the platform and safely descending feet first, were coded “descended”; Approaching time: starting from the moment the infants were placed in the starting position and ending when they reached the edge of the cliff; Latency time: from the moment the infant reached the platform edge until the end of the trial; Tactile exploration time: accumulated duration of periods in which infants’ hands or feet went below the line of the platform, touching the water or reaching down towards the floor, until the moment they touched any other surface (apparatus or own body); Posture of exploration: accumulated duration of periods in which infants assumed a sitting, lying prone, crawling, squatting or upright posture; Pre-Fall posture: posture adopted at the moment the infants fell or locomoted over the platform edge; Retreat behaviour: if after getting to the platform edge infants moved away from it at least once.

本研究采用真实悬崖/水悬崖（Real Cliff / Water Cliff，RC/WC）装置，考察了会爬与会走的婴儿在该装置上的回避行为与探索行为。RC/WC装置为尺寸200×120×75cm的平台，一端设置真实悬崖，另一端则为水悬崖；为保障婴儿安全，实验配备了攀爬防护装备。本研究的核心目的在于探究特定自主运动经验对婴儿规避真实悬崖与水悬崖坠落风险的影响，并对比婴儿在两类悬崖情境下的回避与探索行为差异。

实验采用平衡顺序设计，每名婴儿分别在真实悬崖与水悬崖情境下各完成一次测试。实验者将婴儿放置于平台远离悬崖的一侧边缘附近。实验启动后，若婴儿在最初1分钟内未离开初始位置，实验者仅会在此刻介入，将其移至平台边缘附近。

测试终止的情形包括：(a) 婴儿离开初始位置但未抵达平台边缘，测试持续180秒后结束；(b) 婴儿抵达平台边缘后，测试持续150秒终止；(c) 婴儿从平台边缘跌落或滑下时，测试即刻终止；(d) 婴儿出现烦躁不安或哭闹迹象时，测试终止。

若婴儿在测试前60秒内出现烦躁不安或哭闹症状且无法安抚，则终止测试并将其排除于后续分析之外；若婴儿在抵达平台边缘60秒后出现上述症状，则终止测试，并将该婴儿编码为回避者。在母亲呼唤婴儿的过程中，婴儿可自由活动并探索平台。

婴儿的行为编码包含以下维度：
1. 回避行为：从平台跌落的婴儿编码为"fell"（跌落）；全程停留在平台直至测试结束的婴儿编码为"avoided"（回避）；通过转身、腹部贴靠平台、脚先着地安全下滑等方式调整行为的婴儿编码为"descended"（下滑）。
2. 趋近时长：自婴儿被放置于初始位置起，至其抵达悬崖边缘的时间间隔。
3. 潜伏期时长：自婴儿抵达平台边缘起，至测试结束的时间间隔。
4. 触觉探索时长：婴儿双手或双脚探至平台边缘线以下，触碰水面或探向地面，直至其接触其他表面（实验装置本体或自身身体）的累计时长。
5. 探索姿势：婴儿采取坐姿、俯卧、爬行、蹲姿或直立姿势的累计时长。
6. 跌落前姿势：婴儿跌落或越过平台边缘瞬间所采取的姿势。
7. 退缩行为：婴儿抵达平台边缘后，至少一次主动远离该边缘的行为。