CAT 2021 Slot 1 · VARC · RC passage 1: Cuttlefish and the Marshmallow Test

The full passage and all 4 questions (Q1–Q4) from CAT 2021 Slot 1, with answers and solutions.

The passage below is accompanied by a set of questions. Choose the best answer to each question.

Cuttlefish are full of personality, as behavioral ecologist Alexandra Schnell found out while researching the cephalopod's potential to display self-control. “Self-control is thought to be the cornerstone of intelligence, as it is an important prerequisite for complex decision-making and planning for the future,” says Schnell . . .

[Schnell's] study used a modified version of the “marshmallow test.” During the original marshmallow test, psychologist Walter Mischel presented children between age four and six with one marshmallow. He told them that if they waited 15 minutes and didn’t eat it, he would give them a second marshmallow. A long-term follow-up study showed that the children who waited for the second marshmallow had more success later in life. The cuttlefish version of the experiment looked a lot different. The researchers worked with six cuttlefish under nine months old and presented them with seafood instead of sweets. (Preliminary experiments showed that cuttlefishes’ favorite food is live grass shrimp, while raw prawns are so-so and Asian shore crab is nearly unacceptable.) Since the researchers couldn’t explain to the cuttlefish that they would need to wait for their shrimp, they trained them to recognize certain shapes that indicated when a food item would become available. The symbols were pasted on transparent drawers so that the cuttlefish could see the food that was stored inside. One drawer, labeled with a circle to mean “immediate,” held raw king prawn. Another drawer, labeled with a triangle to mean “delayed,” held live grass shrimp. During a control experiment, square labels meant “never.”

“If their self-control is flexible and I hadn’t just trained them to wait in any context, you would expect the cuttlefish to take the immediate reward [in the control], even if it’s their second preference,” says Schnell . . . and that’s what they did. That showed the researchers that cuttlefish wouldn’t reject the prawns if it was the only food available. In the experimental trials, the cuttlefish didn’t jump on the prawns if the live grass shrimp were labeled with a triangle—many waited for the shrimp drawer to open up. Each time the cuttlefish showed it could wait, the researchers tacked another ten seconds on to the next round of waiting before releasing the shrimp. The longest that a cuttlefish waited was 130 seconds.

Schnell [says] that the cuttlefish usually sat at the bottom of the tank and looked at the two food items while they waited, but sometimes, they would turn away from the king prawn “as if to distract themselves from the temptation of the immediate reward.” In past studies, humans, chimpanzees, parrots and dogs also tried to distract themselves while waiting for a reward.

Not every species can use self-control, but most of the animals that can share another trait in common: long, social lives. Cuttlefish, on the other hand, are solitary creatures that don’t form relationships even with mates or young. “We don’t know if living in a social group is important for complex cognition unless we also show those abilities are lacking in less social species,” says . . . comparative psychologist Jennifer Vonk.

Question 1 · RC Detail and Fact Based Questions

All of the following constitute a point of difference between the “original” and “modified” versions of the marshmallow test EXCEPT that:

  1. A

    the former was performed over a longer time span than the latter.

  2. B

    the former had human subjects, while the latter had cuttlefish.

  3. C

    the former used verbal communication with its subjects, while the latter had to develop a symbolic means of communication.

  4. D

    the former correlated self-control and future success, while the latter correlated self-control and survival advantages.

Pick an option, then check.
Answer & solution

Answer: Option D

We need the one statement that is NOT a real difference between the two versions of the test.

Option 1 is a real difference. Mischel's children waited 15 minutes, and a long-term follow-up study tracked them later in life. The cuttlefish waited at most 130 seconds.

Option 2 is a real difference. The original used children aged four to six; the modified version used six young cuttlefish.

Option 3 is a real difference. Mischel simply told the children what would happen. The researchers 'couldn't explain to the cuttlefish', so they trained them to read shapes (circle, triangle, square) as symbols.

Option 4 is not supported. The first half is true – the follow-up study linked waiting with later success. But the cuttlefish study never links self-control with 'survival advantages'. It only treats self-control as a sign of intelligence. Since the second half is invented, this is not a stated point of difference.

Shortcut: in an EXCEPT question, look for the option with a detail that appears nowhere in the passage. 'Survival advantages' is that detail.

Hence, the answer is option 4.

Question 2 · Strengthen and Weaken Arguments

Which one of the following, if true, would best complement the passage’s findings?
  1. A
    Cuttlefish cannot distinguish between geometrical shapes.
  2. B
    Cuttlefish are equally fond of live grass shrimp and raw prawn.
  3. C
    Cuttlefish wait longer than 100 seconds for the shrimp drawer to open up.
  4. D
    Cuttlefish live in big groups that exhibit sociability.
Pick an option, then check.
Answer & solution

Answer: Option D

The passage's finding is that cuttlefish can show self-control. The open question at the end is how this fits the pattern that most self-controlled animals have 'long, social lives', while cuttlefish are 'solitary creatures'.

Option 4: if cuttlefish actually lived in big, sociable groups, they would fit the pattern seen in humans, chimpanzees, parrots and dogs. The finding would then sit comfortably with what is already known about self-control and social life. This complements the findings.

Option 1 contradicts the experiment. The whole design depends on cuttlefish telling circles, triangles and squares apart.

Option 2 contradicts the preliminary experiments, which showed a clear preference for live grass shrimp over raw prawns. Without that preference, waiting would not show self-control at all.

Option 3 overstates the result. Many cuttlefish waited, but the longest wait was 130 seconds; we cannot say cuttlefish in general wait longer than 100 seconds.

Shortcut: 'complement' means agree with and round off the passage. Rule out every option that clashes with a stated fact; only option 4 is left.

Hence, the answer is option 4.

Question 3 · RC Inference Questions

Which one of the following cannot be inferred from Alexandra Schnell’s experiment?
  1. A
    Cuttlefish exert self-control with the help of diversions.
  2. B
    Intelligence in a species is impossible without sociability.
  3. C
    Cuttlefish exercise choice when it comes to food.
  4. D
    Like human children, cuttlefish are capable of self-control.
Pick an option, then check.
Answer & solution

Answer: Option B

Check each option against what the experiment shows.

Option 1 can be inferred. The cuttlefish sometimes turned away from the king prawn 'as if to distract themselves from the temptation'. That is self-control aided by diversion.

Option 3 can be inferred. Preliminary trials showed a ranking – live grass shrimp first, raw prawn second, Asian shore crab last. So cuttlefish do choose between foods.

Option 4 can be inferred. The experiment adapts the children's marshmallow test, and many cuttlefish waited for the better reward. So, like children, they can exercise self-control.

Option 2 cannot be inferred. The passage says only that most self-controlled animals are social, and Vonk says we do not yet know whether social living matters for complex cognition. In fact, the solitary cuttlefish showing self-control points the other way. 'Impossible' is far too strong.

Shortcut: extreme words like 'impossible' in an inference option are usually the wrong ones, especially when the passage itself is unsure.

Hence, the answer is option 2.

Question 4 · RC - Questions

In which one of the following scenarios would the cuttlefish’s behaviour demonstrate self-control?
  1. A
    raw prawns are released while a live grass shrimp drawer labelled with a square is placed in front of the cuttlefish.
  2. B
    Asian shore crabs and raw prawns are simultaneously released while a live grass shrimp drawer labelled with a triangle is placed in front of the cuttlefish, to be opened after one minute.
  3. C
    raw prawns are released while an Asian shore crab drawer labelled with a triangle is placed in front of the cuttlefish, to be opened after one minute.
  4. D
    live grass shrimp are released while two raw prawn drawers labelled with a circle and a triangle respectively are placed in front of the cuttlefish; the triangle-labelled drawer is opened after 50 seconds.
Pick an option, then check.
Answer & solution

Answer: Option B

Self-control means passing up an immediate, less-liked food to wait for a more-liked one that comes later.

The food ranking is: live grass shrimp (favourite) > raw prawn (so-so) > Asian shore crab (nearly unacceptable). A triangle means 'delayed' and a square means 'never'.

Option 1: a square means the shrimp will never come, so taking the prawn is simply the sensible choice. As the control trial showed, this involves no self-control.

Option 2: prawns and crabs are available now, while the favourite, live grass shrimp, will come after a minute (triangle). Waiting here means giving up an immediate reward for a better delayed one. This is self-control.

Option 3: the immediate food (prawn) is preferred to the delayed food (crab). Taking the prawn now is the natural choice, so no self-control is needed.

Option 4: the favourite, live grass shrimp, is released at once. Nothing better is being held back, so there is no reason to wait.

Shortcut: self-control needs the better food to be the delayed one. Only option 2 meets this.

Hence, the answer is option 2.

Take this paper as a timed test
Real exam timing, instant score, rank and topic-wise analysis.

Practice timed →