Original citation: LoBue, V., & DeLoache, J. S. (2008). Detecting the snake in the grass attention to fear-relevant stimuli by adults and young children. Psychological science, 19(3), 284-289. Description: In their original paper “Detecting the Snake in the Grass - Attention to Fear-Relevant Stimuli by Adults and Young Children”, LoBue & DeLoache (2008) demonstrated in three experiments that detection of fear-relevant stimuli, i.e., snakes, is faster compared with detection of fear-irrelevant stimuli, in both children and adults. As part of the Reproducibility Project: Psychology (Open Science Collaboration, 2015), Alvarez & Pipitone replicated Experiment 3; allthough they registered trends similar to those of the original study, i.e., tendency of both children and adults to react faster to fear-relevant stimuli, the effect sizes were smaller and not statistically significant. Their protocol was not endorsed by the original authors who raised concerns regarding the age of children (ranging from three to five instead including only three year olds) and selection of stimuli; the replication was conducted on a different device (smaller screen), and using different software for presentation and recording of the reaction times. As part of Many Labs 5 project, each collection site will conduct two replications: 1) a direct replication using a non-endorsed protocol from RP:P, ; 2) a direct replication using a new, revised protocol. The protocol will be revised in accordance with the original authors’ suggestions, and will undergo a review process afterwards. The aim is to test whether improvements made in the revised protocol increase reproduciblity. This registration contains our study design, planned sample, and analysis plans. Two versions of this study will be run. They are explained in the Non-endorsed Protocol and Revised Protocol documents (https://osf.io/egjzd/), both of which are saved in the Protocols section. The Summary of Differences Document explains the differences between the two versions and is located in Protocols section. The Revised Protocol contains our sampling plan as well as our analysis plan. Finally, the Materials folder contains the Data collection protocol, description of the stimuli and example of the stimuli, and is located on https://osf.io/f2ra8/ . Target of Replication: In the revised protocol of ML5 replication only 3-year-old children and their parents will be asked to identify either a fear-relevant target (photograph of a snake among frogs) or a fear-irrelevant target (photograph of a frog among snakes). A priori replication criteria: A successful replication will be the one in which both children and adults show propensity in detection for rapid visual detection of fear-relevant stimuli.