dug up in different phases of the£430 million project to extractilmenite, a mineral which can beused to produce titanium dioxidepigment. Around 750,000 tonnesof the ore will be extracted eachyear at the start of the operation,which could last 40 years.

The huge economic growth ofChina has led to an enormousdemand for the white pigment,which is used in paper, paint andplastics, at a time when otherilmenite mines in Australia andSouth Africa are being exhausted.

Tony Juniper, head of Friendsof the Earth in the UK said: “Thisis a very sad day and very badnews for the people ofMadagascar. Rio Tinto isexploiting natural resources in thedeveloping world and, once again,it is the local people who will paythe price.”

Rio Tinto, highly sensitive toconservation criticisms, set up anindependent biodiversitycommittee in order to assess anylikely damage and to see howmuch could be avoided orminimised. As a result, thecompany decided to set aside aconservation area on land that itwas previously going to mine, sothat some of the plants and otherspecies could be protected. Italso worked with experts fromKew Gardens in London topreserve the seeds fromthreatened plants.

Amongst the gloom surroundingmining and other developments,there is some hope that newprojects will help people processfood products grown on the islandinto quality products for the worldmarket. A British company hashelped set up Malagasy, acompany that sells and marketsfinished chocolate bars and, indue course, coffee, herbal teas,honey, nuts and spices under asystem known as Equitrade. NeilKinsall, Malagasy’s marketingdirector says: “All it would take toend poverty in Madagascar is£750 million a year.”

New trading arrangements areseen as a major opportunity tomeet this goal and many believethe alleviation of local humanpoverty is one of the best chancesfor the future survival of theisland’s extraordinary biodiversity.

Current Biology Vol 15 No 17R644

Quick guide

Theory of mindChris Frith and Uta Frith

What is ‘theory of mind’? Maxieats half his chocolate bar andputs the rest away in the kitchencupboard. Then he goes out toplay in the sun. Meanwhile Maxi’smother comes into the kitchen,opens the cupboard and sees thechocolate bar. She puts it in thefridge. When Maxi comes backinto the kitchen, where will he lookfor his chocolate bar? The answerto this question will seem obvious.First, Maxi doesn’t know that hismother has moved the chocolate.Second, Maxi still believes,falsely, that his chocolate is in thecupboard. That is why he looks inthe cupboard. If this is how youanswered the question then youhave a ‘theory of mind’. Wenaturally explain people’sbehavior on the basis of theirminds: their knowledge, their

beliefs and their desires, and weknow that when there is a conflictbetween belief and reality it is thepersons’ belief, not the reality thatwill determine their behavior.Explaining behavior in this way iscalled ‘having a theory of mind’ or‘having an intentional stance.’

What is the advantage of havinga theory of mind? Throughhaving a theory of mind we canrecognize that another person’sknowledge is different from ourown. I know what’s behind therock, but he doesn’t, because,from where he is, he cannot seethat there is a scorpion. Having atheory of mind allows us tomanipulate other people’sbehavior by manipulating theirbeliefs. If he is my friend I canwarn him about the scorpion. If heis my enemy I can tell him it issafe. This latter is called tacticaldeception or Machiavellianism.Human interactions predominantlyinvolve the dissemination of true orfalse knowledge for good or for ill.

Who has a theory of mind? Upto the age of about five years, a

Where will Maxi look for his chocolate? (From the collection of Uta Frith.)

child told the story of Maxi and hismother will say confidently thatMaxi will look for his chocolate inthe fridge. It is as if they assumedthat what they know to be trueeveryone else knows too.Nevertheless, even three-year-olds look first at the cupboardwhen the question is asked, andeven 15-month-olds can beshown to have an inkling of whatis going on; their eye gaze patternshows that they are surprised ifMaxi looks in the fridge. But onlyfrom age five or so do childrenshow full understanding of thesituation and become able toexplain exactly why Maxi has afalse belief.

Children with autism have aspecific problem with theory ofmind tasks. They expect Maxi tolook for his chocolate in thefridge. They reach a mental age ofabout 10 years before theyachieve an understanding of theMaxi task. More complexproblems that involve white lies ordouble bluff take them evenlonger to learn, and they maynever grasp them fully. Theory ofmind difficulties can also beacquired through brain damage infrontal cortex or in the region ofthe temporo-parietal junction.

From field studies there areaccounts of a range of animalsusing tactical deception. But thereis still argument over whethereven chimpanzees show evidenceof this in controlled experiments.The current view is thatchimpanzees may have arudimentary theory of mind, butmonkeys (and other animals)probably do not.

What is so important aboutdeception and false belief inthe study of theory of mind?Having a theory of mind enablesmany important humaninteractions other than deception,in particular teaching. Butdeception is important in thestudy of theory of mind becauseof its association with falsebeliefs. If Maxi’s belief about hischocolate were true — it was stillin the cupboard — then you cancorrectly report where Maxi willlook either by basing thisprediction on what Maxi believes(because you have a theory of

mind) or by basing this predictionon where the chocolate really is(not requiring having a theory ofmind). Thus, when successfullysolving false belief tasks, wherethere is a conflict between thefalse belief and the true state ofaffairs, we can deduce that theoryof mind is engaged.

How is theory of mindpossible? In order to explainpeople’s behavior on the basis oftheir minds, we need to havesome idea of what is in theirminds. The ability to acquireknowledge about other peoples’beliefs and desires is called‘mentalizing’ or ‘mind reading’.Our understanding of themechanisms underlying this abilityremains rudimentary. In everydayspeech we frequently explainbehavior in terms of mentalstates. Maxi will look in thecupboard because that’s wherehe believes his chocolate is andbecause he wants to eat it. Maxidoesn’t know the chocolate is inthe fridge. These everydayexplanations of behavior in termsof mental states are referred to asfolk psychology. Perhaps ourability to mentalize depends uponrepresentations within the brain ofthe propositions that make up thistheory of behavior (referred to astheory theory). On the other hand,perhaps the ability to mentalize isrelated to our capacity toempathize with other people: toput ourselves into their shoes (thisis referred to as simulationtheory).

An influential view is thatmentalizing crucially depends onthe ability to form meta-representations, that is,representations that aredecoupled from reality. Thus thetruth of the statement, ‘Maxibelieves his chocolate is in thecupboard’ does not depend uponwhere the chocolate is in reality. Apossible starting point fordeveloping a mechanistic accountof mentalizing comes from theproblem of perspective taking.The computation of what anotherperson sees from a different pointof view than yours involvestranslation between egocentricand allocentric spatial co-ordinates. This translation is also

fundamental in spatial navigation.It is perhaps no coincidence thatin young children the ability tosolve spatial viewpoint problemsemerges at about the same ageas the ability to solve false belieftasks.

What is the neural basis ofmind reading? There is currentlymuch interest in identifying asocial brain: a circumscribednetwork of brain regionsspecialized for the social domain.Mentalizing is one of a number ofproblems confronting this socialbrain. When brain activity ismeasured during the performanceof a wide range of tasks engagingtheory of mind, two regions havebeen consistently identified: amedial prefrontal region(paracingulate cortex) and thetemporo-parietal junction in thesuperior temporal sulcus.

The medial frontal region is alsoengaged when subjects reflectupon their own mental states, aswell as those of others with themore inferior orbital regionresponding especially toemotional states. The temporo-parietal junction, on the otherhand, seems to have a specialrole in using perceptual cues torecognize the actions andintentions of biological agents.Identification of the precise role ofthese regions awaits thedevelopment of a mechanisticaccount of our remarkable abilityto make inferences about theminds of others.

Where can I find out more?Frith, C.D., and Wolpert, D.M. (Eds).

The Neuroscience of SocialInteraction: Decoding, imitatingand influencing the actions ofothers. Oxford: Oxford UniversityPress.

Nichols, S., and Stich, S. (2003).Mindreading. Oxford: OxfordUniversity Press.

Flavell, J.H. (1999). Cognitivedevelopment: children’s knowledgeabout the mind. Annu. Rev.Psychol. 50, 21–45.

Tomasello, M., Call, J., and Hare, B.(2003). Chimpanzees understandpsychological states - the questionis which ones and to what extent.Trends Cogn. Sci. 7, 153–156.

Functional Imaging Laboratory andInstitute of Cognitive Neuroscience,University College London, London, UK.

Magazine R645