?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Adc&rft.title=A+century+of+generalization&rft.creator=Ghirlanda%2C+Stefano&rft.creator=Enquist%2C+Magnus&rft.subject=Ethology&rft.subject=Animal+Cognition&rft.subject=Animal+Behavior&rft.description=We+review+empirical+data+from+both+ethology+and+psychology+about++generalization%2C+that+is+how+animals+respond+to+sets+of+stimuli+including+familiar+as+well+as+novel+stimuli.+Our+main+conclusion+is+that+many+characteristics+of+generalization+are+universal+behavioural+phenomena%2C+suggesting+that+they+originate+from+general+properties+of+nervous+mechanisms+and%2For+that+evolutionary+strategies+to+cope+with+novelty+and+variability+in+stimulation+are+limited.+We+also+reach+the+following+conclusions.+First%2C+patterns+of+generalization+are+largely+independent%0Aof+systematic+group+(evidence+is+available+for+insects%2C+fish%2C+amphibians%2C+reptiles%2C+birds+and+mammals%2C+including+humans)%2C+behavioural+context+(feeding%2C+drinking%2C+orientation%2C+etc.)%2C+modality+(light%2C+sound%2C+etc.)+and+of+whether+reaction+to+stimuli+is+learned+or+genetically+inherited.+Second%2C+two+major+shapes+of+the+generalization+gradient+can+be+identified%2C+corresponding+to+two+types+of+stimulus+dimensions.+When+changes+in+stimulation+involve+a+rearrangement+of+a+constant+amount+of+stimulation+on+the+sense+organs%2C+the+generalization+gradient+peaks+close+to+familiar+stimuli%2C+and+peak+responding+is+not+much+higher+than+responding+to+familiar+stimuli.+When+the+dimension+involves+increase+or+decrease+of+the+intensity+of+stimulation%2C+the+gradient+is+often+monotonic%2C+and+responding%0Ato+some+novel+stimuli+is+considerably+stronger+than+responding+to+familiar+stimuli%2C+compared+to+non-intensity+dimensions.+Third%2C+rearrangement+gradients+are+better+described+by+Gaussian+curves%2C+rather+than+exponentials%0Aas+often+suggested.+Fourth%2C+when+several+or+many+familiar+stimuli+are+close+to+each+other+interferences+occur%2C+giving+rise+to+predictable+response+biases+such+as+peak+shift+or+supernormality+(interference+between+positive%0Aand+negative+stimuli)%2C+and+stretched+bell+shaped+curves+(several+positive+stimuli).+Lastly%2C+no+principle+differences+between+biases+referred+to+as+peak+shift+and+biases+referred+to+as+supernormal+stimulation+are+found.+The+paper+ends+with+a+discussion+of+theoretical+issues.&rft.date=2003&rft.type=Journal+(Paginated)&rft.type=PeerReviewed&rft.format=application%2Fpdf&rft.identifier=http%3A%2F%2Fcogprints.org%2F5279%2F1%2Fghirlanda_enquist2003.pdf&rft.identifier=++Ghirlanda%2C+Stefano+and+Enquist%2C+Magnus++(2003)+A+century+of+generalization.++%5BJournal+(Paginated)%5D+++++&rft.relation=http%3A%2F%2Fcogprints.org%2F5279%2F