Apes’ and Children’s Understanding of Cooperative and Competitive Communication

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How do apes and humans differ? There are a lot of answers, but one way is communication! Esther Hermann and Michael Tomasello conducted research to test an ape’s ability to understand a human’s communicative motive. To do this they took a look at how an ape interprets pointing. Additionally, the researchers did the same tests to children (18 and 24 months old) and compared the results of the apes to the children!

Hermann and Tomasello used two conditions in their study: informing and prohibiting. The informing condition determined whether the subjects understood a cooperative relationship, while the prohibiting condition determined whether the subject understood a competitive relationship.


Ten chimpanzees and two bonobos were studied using the setting seen in the picture to the right. The hiding spot on the sliding platform is where food would be hidden. The experimenter would point to the cup with the food during each trial.

Each subject first went through a warm-up to make sure they understood what to do. After the warm-up, two experimenters established a relationship with the ape. One was a cooperative relationship for the informing condition, while the other was a competitive relationship for the prohibiting condition, then the trials began.

In the informing condition the experimenter,

  • pointed to the container with food
  • said in a positive tone, ‘Look here
  • alternated looking at the cup and the ape

In the prohibiting condition the experimenter,

  • gestured toward the container with food and in a negative tone said, ‘No, don’t take this one!
  • avoided eye contact with the ape by staring at the container
  • would bang on the glass and pretend to be angry if the ape retrieved the food!

The graph below shows the apes’ combined group scores. Looking at the graph, we see that the apes significantly found more food in the prohibiting condition than in the informing condition. The study concluded that these results suggest apes do not understand a cooperative or friendly cue in the context studied.


The second part of the study evaluated 48 children, half being 24 months old and half being 18 months old. For the children, the set up included a table with boxes, 2 experimenters, and the child’s mother (Figure to the right). A toy was then hidden under a box for the child to find.

The children also went through a warm-up, where the experimenters played with the children so they could be familiar with one another, as well as learn what to do before the trials started. During the trials, experimenter 1 hid the toy, gave an informing or prohibiting cue, and left the room. The child was then able to choose a box by approaching and opening it.

In the informing condition the experimenter,

  • would hide the toy,
  • with a positive tone say, ‘Look here‘,
  • then would alternate looking at the child and the box with the toy

In the prohibiting condition the experimenter,

  • would talk to herself about a toy she was holding, then place it under a box
  • would then give a gesture and in a negative tone say, ‘No, don’t take this one!
  • looked at the box to avoid eye contact with the child

The graph below shows the average percent correct (choosing the box with the hidden toy) for the informing and prohibiting conditions of the children. Looking at the graph, we can see that the 24-month-old children significantly found the toy more in the informing condition than the prohibiting condition, while the 18-month-old children significantly found the toy more in the prohibiting condition!

The study concluded that these results suggest younger children more closely resemble the apes (better comprehension for the prohibiting or competitive condition), while older children are able to comprehend the informing or helpful cue.

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What does this research mean?

This research supports the idea that apes possess more skills in competitive than cooperative contexts. It also supports the idea that humans are able to interact and understand each other in ways apes cannot. That being said, we must remember not every study can account for every single factor that may influence a decision. Therefore, there are limitations in this study.

For example, when conducting the trials, the child is held in their mother’s arms while the ape is secluded. This creates 2 different environments, where the child may get to feel more comfortable with its mother, while the ape is aware of its solitude. Additionally, this study combined results of 2 different ape species (chimpanzees and bonobos), both of which have different characteristics, personalities, and cognitive abilities.

This study provides great information on how apes and children may think and make decisions. But there is still more research to be done and science continues to ask, “What can these creatures do?”

To read the study in full follow the link below.

Apes’ and children’s understanding of cooperative and competitive motives in a communicative situation

Author: Courtney Lewis

Editor: Joclyn Villegas

How Do Humpback Whales Learn Their Songs?

A Review of “Cultural Confusion: Parsimony, Social Learning, and Humpback Whales” By Heidi Lyn


Humpback whales are well known for their elaborate vocal songs, but how do they learn these? Dr. Heidi Lyn – a comparative psychologist studying cognition and communication in non-human animals – has taken a look at how scientists have analyzed this type of communication. She has recently discussed a notable issue with Dr. Mercado’s (2022) parsimonious view on humpback whale song analyses.

Parsimony is the idea that the simplest explanation is often the best, and Mecado’s heavy reliance on two components of parsimony:

  • Parsimony of explanation
  • Parsimony of mechanism

But, these ideas don’t quite fit the ideas of how language can evolve and shift over time. Parsimony of explanation is when the simplest explanation is often the one preferred. Parsimony of mechanism is when the simplest of mechanism is preferred. Occam’s razor is a great place to start, when trying to understand the premise of parsimony and how it is applied to research. 

In contrast to Mecado’s idea surrounding whale song, Lyn provides evidence that social learning and culture may be factors that influence the formation and spread of whale songs. 

Social learning provides an evolutionary upper hand when animals such as the humpback whale can learn from conspecifics rather than having to learn from ground zero (evidence against Mercado’s idea). An example of social learning is imitation, where animals copy behaviors or sounds of another.

Dr. Lyn notes that culture is more difficult to be said as a certain factor, since the definition of culture is debated itself. A popular definition by Whitten et al. (1999) states “A cultural behavior “is one that is transmitted repeatedly through social or observational learning to become a population-level characteristic”. However, not all scientists use this definition. While research continues to clarify “What is culture?“, Dr. Lyn argues that we cannot eliminate this as something humpback whales experience.

Additionally, parsimony of mechanism may not always be the answer. The idea that one mechanism is better than two, does not cover what is expressed by vocal systems that commonly use more than one mechanism of change. These changes in vocal systems are consistent across language and stand in contrast to explanations based on parsimony. In other words, the simplest explanation is arbitrary when understanding vocal communication — it is complex.

Dr. Lyn shows that while parsimony can back explanation on many things, humpback whale song is complex and should remain so. In her publication, Lyn has provided strong evidence that explanations based on parsimony alone are often based on “rhetoric and strong man arguments” and should be taken with a grain of salt.

so what does this mean?

Whale songs are an incredible form of communication! Sometimes, simplifying a system that has many knobs and whistles, maybe simplifying it too much. When we reduce a process down to the bare bones, we can miss out on some really interesting information. If we want to learn more about how intelligent and complex these marine mammals are, then we must allow the idea that they are capable of building a complex system.

To read more, link below.

Reviewed by: Katie West with insight from Dr. Lindsey Johnson

Masking – Are we louder than dolphins?

With human activity increasing both in coastal and deep ocean, the world’s ocean has become quite a noisy environment. Concerned researchers have investigated how this may be impacting marine life, including marine mammals.

One study has investigated the potential effects of pile driving on the dynamics of bottlenose dolphin populations.

Importance of Sound to Bottlenose Dolphins

Bottlenose dolphins use sound to:

  • investigate and understand their environment
  • find and capture prey
  • transmit information to other members or conspecifics

Depending on the surrounding contexts, dolphins will utilize different sound types and project the soundwave at varying frequencies and sound levels (Table 1). Approximately, unmodulated whistles within 3.5-10 kHz have an effective range of 14-25 km. However, when the whistle frequency increases to 12 kHz, the effective range decrease to 1.5-4 km. Pulsed sounds, such as clicks, rarely travel further than a few kilometers.

Table 1.

Sound TypeFrequency Range (kHz)Dominant Frequencies (kHz)Source Level (dB re μPa at 1m)

Sound Generated by Pile Driving

On average, an individual pile driving pulse generates a sound source level of 151 dB re 1 μPa. Dr. Mciwem (2006) summarized potential masking of dolphin call types (i.e., whistles, clicks) in the figure below.

The figure depicts how 3 different frequencies (9, 50, 115 kHz), commonly used by dolphins, dissipates as the sound travels further from the source. Sounds that lie under the lines of the pile driving hammers (i.e., diesel, drop) potentially mask dolphins sounds.

At 9kHz (top panel), the drop hammer could mask vocalizations at a radius of 1.3 km; while the diesel hammer potentially masks vocals over 40 km away.

At 50 kHz, the diesel hammer could mask echolocation clicks up to 6 km away, and the drop hammer up to 0.2 km.

At 115 kHz, the diesel hammer could mask echolocation clicks up to 1.2 km away, and the drop hammer 0 km.

What does this mean?

Here, we see that depending on the loudness of a sound received by and call type – dolphin vocalizations have the potential to be masked or go unheard by a conspecific. Masking may cause dolphins to change the frequency range, loudness or even how often they emit signals. This can cause additional excursion of energy, or possibly change vocal composition of specific social groups. Masking could also influence missed opportunities to mate or receiving vital information from another individual because signals were not heard.

It is important to keep in mind that this information comes a single review study and only goes over potential sound interference from pile driving. However, there are multiple sounds, both natural and human-made, occurring all at once. Therefore, the influence of masking may be underestimated. Scientists continue to do work on understanding the full spectra of masking.


What is a soundscape? Let’s say you step outside your house, a plane flies over head, 5 o’clock traffic is happening down the road, a nice breeze sweeps by and rustles the trees, and your neighbor’s kids are playing with the sprinkler in their front yard — all these sounds coming in and hitting your ear create a “soundscape”.

The combined sounds, that vary in loudness, duration and pitch compose the soundscape for that area. If we were to take the above scenario and put it underwater, all the sounds you hear would be louder, and you perhaps would even hear additional sounds. Sound travels 4.5x faster and travels much further underwater than in air! So, while you may have missed the whispering neighbors at the far end of your street above water, you may now be hearing the gossip below water.

So, what does the ocean sound like? Below gives us a snapshot of different sounds that occur:

Abiotic and biotic sounds are heard throughout the ocean. Weather, such as rain, wind and lightning can create loud or consistent sounds. Earthquakes create noise that can be heard from miles away. Human noise from boats or seismic devices has grown exponentially and can be heard daily. Marine life from corals, fish to large marine mammals emit their own sounds too. Imagine all these sounds being heard at once! This makes for a noisy environment.

Marine mammals use acoustic sounds to communicate with one another. As the background noise of the ocean has drastically increased over the years, scientists have become concerned about potential “masking” of marine mammal acoustic communication.

Examples of soundscape data presentations using an 11-month dataset recorded 20 m off the seabed in 1,280 m of water off Newfoundland, Canada. B: Long term spectral average of the complete dataset. Orange dashed ellipses, presence of seismic survey signals; black solid ellipses, fin whales; solid blue circles, a distant dynamic positioning (DP) vessel signature.

The above figure demonstrates examples of soundscape data taken offshore at Newfoundland, Canada. The figure (B) shows the loudness of different frequencies recorded in the area. Circled are the frequency and timescale ranges for of 3 different sources: dynamic positioning vessel, seismic survey, and fin whale songs. Notice that the noise of the seismic surveys overlaps with fin whale songs.

Not only do some anthropogenic (human-made) sounds fall in the same frequency ranges these animals communicate at, but they are also very loud. Imagine being at a rock concert and trying to talk with your friend. You probably have to shout or get really close; you may even choose to say fewer words because communicating with your voice is not efficient. Your friend may not even understand the words you are saying and ask you to repeat. You may just switch to hand signals or just choose not to communicate until the music stops. Scientists believe marine mammals may be facing similar decisions when trying to communicate to their group members during noisy events.

Marine mammals have been reported to change the frequency and/or duration of their calls – sometimes ceasing all communication – when they are in the presence of loud anthropogenic noise. This can lead to serious impacts:

  • exerting extra energy to try and send audible calls
  • missing important calls that may indicate food or a mate
  • temporary or permanent shifts in behavior
  • temporary or permanent avoidance or relocation

It is important for scientists, decision-makers, boaters and even recreational swimmers to continue to work together to reduce the noise we impart into the ocean. Remember it is louder and travels much further than you may think, so we must keep in mind the animal’s perspective and allow them to live out their natural behaviors as best as possible.

For additional information on soundscapes and research click here.