Table 1.

Summary of points examined in this review.

Transmission process	Known influential factors	Directions for further studies
Initiation	– Producer characteristics (sex, age, dominance rank, and personality, motivation),	– Competing solutions to the same problem
	– Environment (complexity, stability),	– Suboptimal demonstrator characteristics
	– Type of innovation	– Seeding of information to individuals with different characteristics simultaneously
Pathway	– Producer/receiver characteristics	As above, and:
	– Producer/receiver relationships (kinship, dominance difference, “friendship”)	– Several information of varied types (e.g., social/asocial), qualities, relevance, or congruence presented at the same time
	– Cognitive abilities (sensory output and processing)	– Social structure disturbance/manipulation (e.g., alone/in a social setting)
	– Social network (openness, connectedness, tolerance)	– Same type of experiments to many different species/groups (including interspecies)
	– Adaptive value	– Different task complexity/difficulty concurrently
	– Information characteristics
Establishment/termination	– Cost/benefit ratio,	– Comparison between initial transmission and long-term transmission patterns
	– Conservatism level
	– Social network structure
Additional aspects:
– Technological equipment to track non-invasively: individuals’ movements (GPS, accelerometer), physical states (heart rate monitor, blood glucose or glucocorticoid level monitor, infrared imaging), social proximities [radio-frequency identification (RFID) tags]
– Test apparatus version 2.0 with touch screens or panels, automated feeders, eye-trackers, face recognition
– Long-term population studies
– Heritability/evolution/environmental changes studies
– Taking inspiration in other diffusion domains such as epidemiology, informatics, or social media
– Building a database of protocols, pre-print, and published studies