According to Culum Brown from Macquarie University, "Fish are more intelligent than they appear. In many areas, such as memory, their cognitive powers match or exceed those of ‘higher’ vertebrates including non-human primates."
Fish captured by anglers has been shown to cause decreases in catchability. This therefore indicates that fish use their memory of negative experiences to associate capture with the stress response and therefore become less easy to catch.
This learning has been shown not just in carp but also paradise fish (Macropodus opercularis) which avoid places where they have experienced a single attack by a predator and continue to do so for many months. Also, several fish species are capable of learning complex spatial relationships and forming mental maps  and integrate experiences which enable the fish to generate appropriate avoidance responses. This means that a fish can exhibit strong aversive behavior if exposed to tissue damage or a predator. As a result, any reduction in the stressfulness of a capture by an angler, should be beneficial to angling in the long-term, since recapture of the fish should be less difficult.
- Brown, Culum (2004) Not just a pretty face New scientist, 2451: 42-43.
- Beukema, J.J. (1970). Angling experiments with carp: decreased catchability through one trial learning. Netherlands Journal of Zoology, 20: 81–92.
- Beukema, J.J. & Vos, G.J. (1974). Experimental tests of a basic assumption of the capture-recapture method in pond populations of carp Cyprinus carpio L.. Journal of Fish Biology, 6(3): 317.
- Raat, A.J.P. (1985). Analysis of angling vulnerability of common carp, Cyprinus carp /0 L., in catch-and-release angling in ponds. Aquaculture Research, 16(2): 171-187.
- Czanyi, V. & Doka, A. (1993). Learning interactions between prey and predator fish. Marine Behavior and Physiology, 23: 63–78.
- Odling-Smee, L. & Braithwaite, V. A. (2003). The role of learning in fish orientation. Fish and Fisheries, 4: 235–246.
- Portavella, M. Torres, B. & Salas, C. (2004). Avoidance response in goldfish: emotional and temporal involvement of medial and lateral telencephatic pallium. The Journal of Neuroscience, 24: 2342–2335.
- Yue, S. Moccia, R.D. & Duncan, I.J.H. (2004). Investigating fear in domestic rainbow trout, Oncorhynchus mykiss, using an avoidance learning task. Applied Animal Behavior Science, 87: 343–354.
- The Times Smart school of fish expose stupidity of a popular myth TimesOnline, 22 November 2006.
- Braithwaite, Victoria A (2005) "Cognitive ability in fish" Fish physiology, 24: 1–37.
- Brown, Culum; Laland, Kevin and Krause Jens (Eds) (2006) Fish Cognition and Behavior Wiley-Blackwell. ISBN 978-1-4051-3429-3
- Fish aren't thick: scientist The Sydney Morning Herald, September 12, 2006.
- Fishy Machiavellis swim rings around anglers TimesOnline, September 1, 2003.
- Brown C, Laland K, Krause J (2003) Learning in fishes: why are they smarter than you think? Fish and Fisheries, 4:197–288.
- Brown, C and Laland, K (2003) "Social learning in fishes: A review" Fish and Fisheries, 4(3), 280-288.
- Huntingford FA, C Adams, VA Braithwaite, S Kadri, TG Pottinger, P Sandøe and JF Turnbull (2006) "Review paper: Current issues in fish welfare" Journal of fish
- Laland, K., Brown, C. and Krause J. (2003) "Learning in Fishes: An introduction" Fish and Fisheries, 4(3): 199-202.
- Schultz, Nora (2007) "When fish get emotional" New Scientist.
- Researchers find fish that can count up to four The Guardian, 26 February 2008.